CCTV and clearance rates paper published

My paper with Yeondae Jung, The effect of public surveillance cameras on crime clearance rates, has recently been published in the Journal of Experimental Criminology. Here is a link to the journal version to download the PDF if you have access, and here is a link to an open read access version.

The paper examines the increase in case clearances (almost always arrests in this sample) for incidents that occurred nearby 329 public CCTV cameras installed and monitored by the Dallas PD from 2014-2017. Quite a bit of the criminological research on CCTV cameras has examined crime reductions after CCTV installations, which the outcome of that is a consistent small decrease in crimes. Cameras are often argued to help solve cases though, e.g. catch the guy in the act. So we examined that in the Dallas data.

We did find evidence that CCTV increases case clearances on average, here is the graph showing the estimated clearances before the cameras were installed (based on the distance between the crime location and the camera), and the line after. You can see the bump up for the post period, around 2% in this graph and tapering off to an estimate of no differences before 1000 feet.

When we break this down by different crimes though, we find that the increase in clearances is mostly limited to theft cases. Also we estimate counterfactual how many extra clearances the cameras were likely to cause. So based on our model, we can say something like, a case would have an estimated probability of clearance without a camera of 10%, but with a camera of 12%. We can then do that counterfactual for many of the events around cameras, e.g.:

Probability No Camera   Probability Camera   Difference
    0.10                      0.12             + 0.02
    0.05                      0.06             + 0.01
    0.04                      0.10             + 0.06

And in this example for the three events, we calculate the cameras increased the total expected number of clearances to be 0.02 + 0.01 + 0.06 = 0.09. This marginal benefit changes for crimes mostly depends on the distance to the camera, but can also change based on when the crime was reported and some other covariates.

We do this exercise for all thefts nearby cameras post installation (over 15,000 in the Dallas data), and then get this estimate of the cumulative number of extra theft clearances we attribute to CCTV:

So even with 329 cameras and over a year post data, we only estimate cameras resulted in fewer than 300 additional theft clearances. So there is unlikely any reasonable cost-benefit analysis that would suggest cameras are worthwhile for their benefit in clearing additional cases in Dallas.

For those without access to journals, we have the pre-print posted here. The analysis was not edited any from pre-print to published, just some front end and discussion sections were lightly edited over the drafts. Not sure why, but this pre-print is likely my most downloaded paper (over 4k downloads at this point) – even in the good journals when I publish a paper I typically do not get 1000 downloads.

To go on, complaint number 5631 about peer review – this took quite a while to publish because it was rejected on R&R from Justice Quarterly, and with me and Yeondae both having outside of academia jobs it took us a while to do revisions and resubmit. I am not sure the overall prevalence of rejects on R&R’s, I have quite a few of them though in my career (4 that I can remember). The dreaded send to new reviewers is pretty much guaranteed to result in a reject (pretty much asking to roll a Yahtzee to get it past so many people).

We then submitted to a lower journal, The American Journal of Criminal Justice, where we had reviewers who are not familiar with what counterfactuals are. (An irony of trying to go to a lower journal for an easier time, they tend to have much worse reviewers, so can sometimes be not easier at all.) I picked it up again a few months ago, and re-reading it thought it was too good to drop, and resubmitted to the Journal of Experimental Criminology, where the reviews were reasonable and quick, and Wesley Jennings made fast decisions as well.

Bias and Transparency

Erik Loomis over at the LGM blog writes:

It’s fascinating to be doing completely unfundable research in the modern university. It means you don’t matter to administration. At all. You are completely irrelevant. You add no value. This means almost all humanities people and a good number of social scientists, though by no means all. Because universities want those corporate dollars, you are encouraged to do whatever corporations want. Bring in that money. But why would we trust any research funded by corporate dollars? The profit motive makes the research inherently questionable. Like with the racism inherent in science and technology, all researchers bring their life experiences into their research. There is no “pure” research because there are no pure people. The questions we ask are influenced by our pasts and the world in which we grew up. The questions we ask are also influenced by the needs of the funder. And if the researcher goes ahead with findings that the funder doesn’t like, they are severely disciplined. That can be not winning the grants that keep you relevant at the university. Or if you actually work for the corporation, being fired.

And even when I was an unfunded researcher at university collaborating with police departments this mostly still applied. The part about the research being quashed was not an issue for me personally, but the types of questions asked are certainly influenced. A PD is unlikely to say ‘hey, lets examine some unintended consequences of my arrest policy’ – they are much more likely to say ‘hey, can you give me an argument to hire a few more guys?’. I do know of instances of others people work being limited from dissemination – the ones I am familiar with honestly it was stupid for the agencies to not let the researchers go ahead with the work, but I digress.

So we are all biased in some ways – we might as well admit it. What to do? One of my favorite passages in relation to our inherent bias is from Denis Wood’s introduction to his dissertation (see some more backstory via John Krygier). But here are some snippets from Wood’s introduction:

There is much rodomontade in the social sciences about being objective. Such talk is especially pretentious from the mouths of those whose minds have never been sullied by even the merest passing consideration of what it is that objectivity is supposed to be. There are those who believe it to consist in using the third person, in leaning heavily on the passive voice, in referring to people by numbers or letters, in reserving one’s opinion, in avoiding evaluative adjectives or adverbs, ad nauseum. These of course are so many red herrings.

So we cannot be objective, no point denying it. But a few paragraphs later from Wood:

Yet this is no opportunity for erecting the scientific tombstone. Not quite yet. There is a pragmatic, possible, human out: Bare yourself.

Admit your attitudes, beliefs, politics, morals, opinions, enthusiasms, loves, odiums, ethics, religion, class, nationality, parentage, income, address, friends, lovers, philosophies, language, education. Unburden yourself of your secrets. Admit your sins. Let the reader decide if he would buy a used car from you, much less believe your science. Of course, since you will never become completely self-aware, no more in the subjective case than in the objective, you cannot tell your reader all. He doesn’t need it all. He needs enough. He will know.

This dissertation makes no pretense at being objective, whatever that ever was. I tell you as much as I can. I tell you as many of my beliefs as you could want to know. This is my Introduction. I tell you about this project in value-loaded terms. You will not need to ferret these out. They will hit you over the head and sock you in the stomach. Such terms, such opinions run throughout the dissertation. Then I tell you the story of this project, sort of as if you were in my – and not somebody else’s – mind. This is Part II of the dissertation. You may believe me if you wish. You may doubt every word. But I’m not conning you. Aside from the value-loaded vocabulary – when I think I’ve done something wonderful, or stupid, I don’t mind giving myself a pat on the back, or a kick in the pants. Parts I and II are what sloppy users of the English language might call “objective.” I don’t know about that. They’re conscientious, honest, rigorous, fair, ethical, responsible – to the extent, of course, that I am these things, no farther.

I think I’m pretty terrific. I tell you so. But you’ll make up your mind about me anyway. But I’m not hiding from you in the the third person passive voice – as though my science materialized out of thin air and marvelous intentions. I did these things. You know me, I’m

Denis Wood

We will never be able to scrub ourselves clean to be entirely objective – a pure researcher as Loomis puts its. But we can be transparent about the work we do, and let readers decide for themselves whether the work we bring forth is sufficient to overcome those biases or not.

Ask me anything

So I get cold emails probably a few times a month asking random coding questions (which is perfectly fine — main point of this post!). I’ve suggested in the past that folks use a few different online forums, but like many forums I have participated in the past they died out quite quickly (so are not viable alternatives currently).

I think going forward I will mimic what Andrew Gelman does on his blog, just turn my responses into blog posts for everyone (e.g. see this post for an example). I will of course ask people permission before I post, and omit names same as Gelman does.

I have debated over time of doing a Patreon account, but I don’t think that would work very well (imagine I would get 1.2 subscribers for $3 a month!). Ditto for writing books, I debate on doing a Data Science for Crime Analysts in Python or something along those lines, but then I write the outline and think that is too much work to have at best a few hundred people purchase the book in the end. I will do consulting gigs for folks, but the majority of questions people ask do not take long enough to justify running a tab for the work (and I have no desire to rack up charges for grad students asking a few questions).

So feel free to ask me anything.

Open source code projects in criminology

TLDR; please let me know about open source code related criminology projects.

As part of my work with CrimRxiv, we have started the idea of creating a page to link to various open source criminology focused projects. That is overly broad, but high level here we are thinking for pragmatic resources (e.g. code repositories/packages, open source text books), as opposed to more traditional literature.

As part of our overlay journal we are starting, D1G1TAL & C0MPUTAT10NAL CR1M1N0L0GY, we are trying to get folks to submit open source work for a paper. (As a note, this will not have any charges to publish.) The motivation is two-fold: 1) this gives a venue to get your code peer reviewed (e.g. similar to the Journal of Open Source Software). This is mainly for the writer, to give academic recognition for your open source work. 2) Is for the consumer of the information, it is a nice place to keep up on current developments. If you write an R package to do some cool analysis I want to be aware of it!

For 2, we can accomplish something similar by just linking to current projects. I have started a spreadsheet of links I am collating for now, (in the future will update to this page, you need to be signed into CrimRxiv to see that list). For examples of the work I have collated so far:

Then we have various R packages from folks floating around; Greg Ridgeway, Jerry Ratcliffe, Wouter Steenbeek (as well as the others I mentioned previously you can check out their other projects on Github). Please add in info into the google spreadsheet, comment here, or send me an email if you would like some work you have done (or know others have done) that should be added.

Again I want to know about your work!

Academia and the culture of critiquing

Being out of academia for a bit now gives me some perspective on common behaviors I now know are not normal for other workplaces. Andrew Gelman and Jessica Hullman’s posts are what recently brought this topic to mind. Both what Jessica (and other behavior Andrew Gelman points out commonly on his blog) are near synonymous with my personal experience at multiple institutions. So even though we all span different areas in science it appears academic culture is quite similar across places and topical areas.

One in academia is senior academics shirking responsibility – deadwoods. This behavior I can readily attribute to rational behavior, so although I found it infuriating it was easily explainable. Hey, if you let me collect a paycheck into my 90’s I would likely be a deadwood at that point too! (Check out this Richard Larson post on why universities should encourage more professors to be semi-retired.)

Another behavior I had a harder time wrapping my head around was what I will refer to as the culture of critique. To the extent that we have a scientific method, a central component of that is to be critical of scientific results. If I read a news article that says X made crime go up/down, my immediate thought is ‘there needs to be more evidence to support that assertion’.

That level of skepticism is a necessary component of being an academic. We apply this skepticism not only to newspaper articles, but to each other as well. University professors don’t really have a supervisor like normal jobs, we each evaluate our peers research through various mechanisms (peer review journal articles, tenure review, reviewing grant proposals, critique public presentations, etc.).

This again is necessary for scientific advancement. We all make mistakes, and others should be able to rightly go and point out my mistakes and improve upon my work.

This bleeds out though in several ways that negatively impact academics ability to interact with one another. I don’t really have a well scoped out outline of these behaviors, but here are several examples I’ve noticed over time (in no particular order):

1) The person receiving critiques cannot distinguish between personal attacks and legitimate scientific ones. This has two parts, one is that even if you can distinguish between the two in your mind, they make you feel like shit either way. So it doesn’t really matter if someone gives a legitimate critique or someone makes ad hominem attacks – they each are draining on your self-esteem the same way.

The second part is people actually cannot tell the difference in some circumstances. In replication work on fish behavior pointing out potential data fabrication, some scientists response is that it is intentionally cruel to critique prior work. Original researchers often call people who do replications data thugs or shameless bullies, impugning the motives of those who do the critiques. For a criminology example check out Justin Pickett’s saga trying to get his own paper retracted.

To be fair to the receiver of critiques, in critiques it is not uncommon to have a mixture of legitimate and personal attacks, so it is reasonable to not know the difference sometimes. I detail on this blog on a series of back and forth on officer involved shooting research how several individuals from both sides again have their motivations impugned based on their research findings. So 2) the person sending critiques cannot distinguish between legitimate scientific critique and unsubstantiated personal attacks.

One of the things that is pretty clear to me – we can pretty much never have solid proof into the motives or minds of people. We can only point out either logical flaws in work, or in the more severe case of forensic numerical work can point out inconsistencies that are at best gross negligence (and at worse intentional malfeasance). It is also OK to point out potential conflicts of interest of course, but relying on that as a major point of scientific critique is often pretty weak sauce. So while I cannot define a bright line between legitimate and illegitimate critique, I don’t think in practice the line is all that fuzzy.

But because critiquing is a major component of many things we do, we have 3) piling on every little critique we can think of. I’ve written about how many reviewers have excessive complaints about minutia in peer reviews, in particular people commonly critique clearly arbitrary aspects of writing style. I think this is partly a function of even if people really don’t have substantive things to say, they go down the daisy chain and create critiques out of something. Nothing is perfect, so everything can be critiqued in some way, but clearly what citations you included are rarely a fundamental aspect of your work. But that part of your work is often the major component of how you are evaluated, at least in terms of peer reviewed journal articles.

This I will admit is a harder problem though – personal vs legitimate critiques I don’t think is that hard to tell the difference – but what counts as a deal breaker vs acceptable problem with some work is a harder distinction to make. This results in someone being able to always justify rejecting some work on some grounds, because we do not have clear criteria for what is ‘good enough’ to publish, ‘justified enough’ to get a grant, ‘excellent enough’ to get an award, etc.

4) The scarlet mark. Academics have a difficult time separating out critiques on one piece of research vs a persons work as a whole. This admittedly I have the weakest evidence of widespread examples across fields (only personal anecdotes really, the original Gelman/Hullman posts point out some similar churlish behavior though, such as asking others to disassociate themselves), but it was common in my circle of senior policing scholars to critique other younger policing scholars out of hand. It happened to me as well, senior academics saying directly to me based on the work I do I shouldn’t count as a policing scholar.

Another common example I came across was opinions of the Piquero’s and their work. It would be one thing to critique individual papers, often times people dismissed their work offhand because they are prolific publishers.

This is likely also related to network effects. If you are in the right network, individuals will support you and defend your work (perhaps without regards to the content). Whereas if you are in an outside network folks will critique you. Because it is fair game to critique everything, and there are regular norms in peer review to critique things that are utterly arbitrary, you can sink a paper for what appears to be objective reasons but is really you just piling on superficial critiques. So of course if you have already decided you do not like someone’s work, you can pile on whatever critiques you want with impunity.

The final behavior I will point out, 5) never back down or admit faults. For a criminal justice example, I will point out an original article in JQC and critique in JQC about interaction effects. So the critique by Alex Reinhart was utterly banal, it was that if you estimate a regression model:

y = B1*[ log(x1*x2*x3) ]

This does not test an interaction effect, quite the opposite, it forces the effects to be equal across the three variables:

y = B1*log(x1) + B1*log(x2) + B1*log(x3)

Considering a major hypothesis for the paper was testing interaction effects, it was kind of a big deal for interpretations in the paper. So the response by the original authors should have been ‘Thank you Alex for pointing out our error, here are the models when correcting for this mistake’, but instead we get several pages of of non sequiturs that attempt to justify the original approach (the authors confuse formative and reflective measurement models, and the distribution of your independent variables doesn’t matter in regression).

To be fair this never admit you are wrong behavior appears to be for everyone, not just academics. Andrew Gelman on his blog often points to journalists refusing to correct mistakes as well.

The irony of never back down is that since critique is a central part of academia, you would think it would also be normative to say ‘ok I made a mistake’ and/or ‘OK I will fix my mistake you pointed out’. Self correcting is surely a major goal of critiques and I mean we all make mistakes. But for some reason admitting fault is not normative. Maybe because we are so used to defending our work through a bunch of nonsense (#2) we also defend it even when it is not defensible. Or maybe because we evaluate people as a whole and not individual pieces of work (#4) we need to never back down, because you will carry around a scarlet mark of one bad piece forever. Or because we ourselves cannot distinguish between legitimate/illegitimate (#1), people never back down. I don’t know.

So I am sure a sociologist who does this sort of analysis for a living could make sense of why these behaviors exist than me. I am simply pointing out regular, repeated interactions I had that make life in academia very mentally difficult.

But again I think these are maybe intrinsic to the idea that skepticism and critiquing are central to academia itself. So I don’t really have any good thoughts on how to change these manifest negative behaviors.

Reproducible research and code review for journals

Recently came across two different groups broaching the subject of code reviews and reproducible research more broadly for criminal justice. There are certainly aspects of either that make it difficult in the context of peer review. But I am not one to let the perfect be the enemy of the good, so I will layout the difficulties and give some comments on potential good enough solutions that still make marked improvements on the current state of affairs in crim/cj research.

Reproducible Research

So what do I mean by reproducible research? Jeromy Anglim on crossvalidated has a good breakdown on different ways we may apply the term. So to some it may mean if you did a hot spots policing experiment, can I replicate the same crime reduction results in another city.

These are important to publish (simply because social science experiments will inevitably have quite a bit of variance), but this is often not what we are talking about when we talk about replication. We are often talking about a much smaller in scope goal – if I give you the exact same data, can you reproduce the tables/figures in the manuscript you used to make your inferences?

One problem that is often the case with CJ research is that we are working with sensitive data. If I do analysis on a survey of a sensitive topic, I often cannot share the data. But, I do not believe that should entirely put a spike in the question of reproducible data. I have broken down different levels that are possible in making research more reproducible:

  1. A Sharing data and code files to reproduce the paper results
  2. B Sharing code files and simulated data that illustrate the results
  3. C Sharing the plain-text log files showing the code and results of tables/figures

So I have not seen C proposed anywhere, but it is a dead simple solution that almost everyone should be able to accommodate. It simply involves typing log using "output.txt", text at the top of your Stata file, or OUTPUT EXPORT /PDF DOCUMENTFILE="output.pdf" at the end of your SPSS analysis (or could be done via the GUI), etc. These are the log/output files used to generate the results you report in the paper, and typically contain both the commands run, as well as the resulting tables. These files can quite easily not contain privileged information (in fact they won’t be default most of the time, unless you printed out individual names in a table for example in intermediate results).

To accomplish C does take some modicum of wherewithal in terms of writing code, but it is a pretty low bar. So I see no reason why all quantitative analyses cannot require at least this step right now. I realize it is not foolproof – a bad actor could go and edit the results (same as they could edit the results without this information). But it ups the level of effort to manipulate results by quite a bit, and more importantly has the potential to catch more mundane transcription errors that occur quite frequently.

Sometimes I want more details on the code used, the nature of the data etc. (Most quasi-experimental design for example can be summed up as shape your data in a special way and run a particular regression model.) For people like me who care about that, B helps with that, in that I can see the code front-to-back, can actually go and inspect the shape and values in a particular rectangular dataset, and see how the code interacts with those objects. The only full on example of this I am aware of is a recent example paper in Nature Behavior that shares the code using simulated data.

B is also very similar to people who release statistical packages to reproduce their code. So if you release an R package that conducts your new fancy technique, even if you can’t share your data it is really good for people to be able to view the underlying code even by itself to understand the technique better and in conjunction build on your work more. If you do a new technique, it is a crazy ton of work to replicate that on your own, so most people will not bother.

A is most of the way there to the gold standard – if you can share both the data and the code used to reproduce the analysis. Both A and B take a significant amount of knowledge of statistical programming to accomplish. Most people in our field do not have the skills to write an analysis front-to-back that can run in a series of scripts though. To get to A/B grad programs in crim/cj need to spend crazy more time on teaching these skills, which is near zero now almost across the board.

One brief thing to mention about A is that the boundary is difficult to define. So for example, I share code to reproduce analysis in my 311 and crime at micro places in DC paper (paper link, code). But this starts from a dataset that has the street units in DC and all of the covariates already compiled. But where did that dataset come from? I created it by compiling many different sources, so the base dataset is itself very difficult to replicate. Again not letting the perfect be the enemy of the good, I think just starting from your compiled dataset, and replicating the tables/graphs in the manuscript is better than letting the fuzzy boundary prevent you from sharing anything.

Code Reviews for Journal Submissions

The hardest part of A is that even after you share your data, some journals want to be able to run the code locally to entirely reproduce your results. So while I have shared data code (A above) for many papers, see this spreadsheet, they have not been externally vetted by any of those journals. This vetting is the standard in some economic journals now I believe, and would not be surprised in some poli-sci journals as well. This is a very hard problem though, and requires significant resources from both the journal and the researcher to be able to do that.

The biggest hurdle is that even if you share your data/code, your particular system may be idiosyncratic. You may have different R libraries installed than me. You may have different versions of python packages. I may have used a program on Windows to do some analysis you cannot do on a Mac. You may rely on some paid API I cannot access.

These are often solvable problems, but take quite a bit of time to work out. A comparable example to my work is when data scientists say ‘going to production’. This often involves taking some analysis I did on my local machine, and making it run autonomously on my companies servers. There are some things that make it more or less difficult than the typical academic situation, but I think it is broadly comparable. To go to production for a project will typically take me 3-6 months at 50% of my time, so maybe something like 300 hours for a lowish end estimate. And that is just the time it takes from the researchers end, from the journals end it will also take a significant amount of time to compile every ones code and verify the results.

Because of this, I don’t think the fully reproducible re-run my code and generate the exact same tables are feasible in the current way we do academic research and peer review. But again that is why I list C above – we shouldn’t let the perfect be the enemy of the good.

Validating New Empirical Techniques

The code review above is not really code review in the sense that someone looks at your code and says this is correct, it is simply just saying can I get the same results as you. You may want peer review to accomplish the task of not only saying is it reproducible, but is it valid/correct? There are a few things towards this end I would like to see more often in crim/cj. I realize we are not statistics, so cannot often ask for formal proofs. But there are simpler things we can do to verify the results. These are the responsibility of the researcher to provide, not the reviewer to script up on their own to validate someone elses work.

One, illustrate the technique using a very simplified example. So for instance, in my p-median patrol areas paper, I show an example of constructing the linear program with only four areas. You should be able to calculate what the result should be by hand, so can verify the correctness of your algorithm. This has the added benefit of being a very good pedagogical way to describe your method.

Two, illustrate the technique on a larger sample of simulated data in which you again know the correct result. For one example of this, I showed how to estimate group based trajectory models using deep learning libraries. Again your model/method should be able to recover the correct result (which you know) given the simulated fake data.

Three, validate the result using real data compared to the current standard. For crime mapping papers, this means comparing forecasts compared to RTM, or simpler regression models, or simply prior crime = future crime on out of sample data. Amazingly many machine learning papers in CJ do not do out of sample predictions. If it is an inferential procedure, comparing the results to some other status quo technique is similar, such as showing conformal prediction intervals have smaller widths (so more statistical power) than placebo results for synthetic control designs (at least for that example with state panel level crime data).

You may not have all three of these examples in any particular paper, but I think for very new techniques 1 or 2 is necessary. 3 is often a by-product on the analysis anyway. So I do not believe any of these asks are that onerous. If you have the skills to create some new technique, you should be able to accomplish 1 or 2.

I do not have any special advice in terms of the reviewers perspective. When I do code reviews at work, what we do is go line by line, and my co-workers give high level design advice. E.g. you should use a config file for this instead of defining it inline, you should turn this block into a function, you should make a class to open/close the database connections etc. The code reviews do not validate the technical correctness, so if I queried the wrong data they wouldn’t know in the code review. The proof is in the pudding so to speak, so if my results are performing really badly in the real world I know I am doing something wrong. (And the obverse, if my results are on the mark and making money I am pretty sure I did nothing terribly wrong.)

Because there are not these real world mechanisms to validate code in peer reviewed papers, my suggestions for 1/2/3 are the closest I think we can get in many circumstances. That and simply making your code available will dramatically improve the reproducibility and validity of your research compared to the current status quo in our field.

Publishing in Peer Review?

I am close, but not quite, entirely finished with my current crim/cj peer reviewed papers. Only one paper hangs on, the CCTV clearance paper (with Yeondae Jung). Rejected twice so far (once on R&R from Justice Quarterly), and has been under review in toto around a year and a half so far. It will land somewhere eventually, but who knows where at this point. (The other pre-prints I have on my CV but are not in peer review journals I am not actively seeking to publish anymore.)

Given the typical lags in the peer review process, if you look at my CV I will appear active in terms of publishing in 2020 (6 papers) and 2021 (4 papers and a book). But I have not worked on any peer review paper in earnest since I started working at HMS in December 2019, only copy-editing things I had already produced. (Which still takes a bit of work, for example my Cost of Crime hot spots paper took around 40 hours to respond to reviewers.)

At this point I am not sure if I will pursue any more peer reviewed publications directly in criminology/criminal justice. (Maybe as part of a team in giving support, but not as the lead.) Also we have discussed at my workplace pursuing publications, but that will be in healthcare related projects, not in Crim/CJ.

Part of the reason is that the time it takes to do a peer review publication is quite a bit relative to publishing a simple blog post. Take for instance my recent post on incorporating harm weights into the WDD test. I received the email question for this on Wednesday 11/18, thought about how to tackle the problem overnight, and wrote the blog post that following Thursday morning before my CrimCon presentation, (I took off work to attend the panel with no distractions). So took me around 3 hours in total. Many of my blog posts take somewhat longer, but I definitely do not take any more than 10-20 hours on an individual one (that includes the coding part, the writing part is mostly trivial).

I have attempted to guess as to the relative time it takes to do a peer reviewed publication based on my past work. I averaged around 5 publications per year, worked on average 50 hours a week while I was an academic, and spent something like I am guessing 60% to 80% (or more) of my time on peer review publications. Say I work 51 weeks a year (I definitely did not take any long vacations!, and definitely still put in my regular 50 hours over the summertime), that is 51*50=2550 hours. So that means around (2550*0.6)/5 ~ 300 or (2550*0.8)/5 ~ 400 so an estimate of 300 to 400 hours devoted to an individual peer review publication over my career. This will be high (as it absorbs things like grants I did not get), but is in the ballpark of what I would guess (I would have guessed 200+).

So this is an average. If I had recorded the time, I may have had a paper only take around 100 hours (I don’t think I could squeeze any out in less than that). I have definitely had some take over 400 hours! (My Mapping RTM using Machine Learning I easily spent over 200 hours just writing computer code, not to brag, it was mostly me being inefficient and chasing a few dead ends. But that is a normal part of the research process.)

So it is hard for me to say, OK here is a good blog post that took me 3 hours. Now I should go and spend another 300 to write a peer review publication. Some of that effort to publish in peer review journals is totally legitimate. For me to turn those blog posts into a peer review article I would need a more substantive real-life application (if not multiple real-life applications), and perhaps detailed simulations and comparisons to other techniques for the methods blog posts. But a bunch is just busy work – the front end lit review and answering petty questions from peer reviewers is a very big chunk of that 300 hours (and has very little value added).

My blog posts typically get many more views than my peer review papers do, so I have very little motivation to get the stamp of approval for peer review. So my blog posts take far less time, are more wide read, and likely more accessible than peer reviewed papers. Since I am not on the tenure track and do not get evaluated by peer reviewed publications anymore, there is not much motivation to continue them.

I do have additional ideas I would like to pursue. Fairness and efficiency in siting CCTV cameras is a big one on my mind. (I know how to do it, I just need to put in the work to do the analysis and write it up.) But again, it will likely take 300+ hours for me to finish that project. And I do not think anyone will even end up using it in the end – peer reviewed papers have very little impact on policy. So my time is probably better spent writing a few blog posts and playing video games with all the extra time.

If you are an editor reading this, I still do quite a few peer reviews (so feel free to send me those). I actually have more time to do those promptly since I am not hustling writing papers! I have actually debated on whether it is worth it to start my own peer reviewed journal, or maybe contribute to editing an already existing journals (just joined the JQC editorial board). Or maybe start writing my own crime analysis or methods text books. I think that would be a better use of my time at this point than pursuing individual publications.

Lit reviews are (almost) functionally worthless

The other day I got an email from ACJS about the most downloaded articles of the year for each of their journals. For The Journal of Criminal Justice Education it was a slightly older piece, How to write a literature review in 2012 by Andrew Denney & Richard Tewksbury, DT from here on. As you can guess by the title of my blog post, it is not my most favorite subject. I think it is actually an impossible task to give advice about how to write a literature review. The reason for this is that we have no objective standards by which to judge a literature review – whether one is good or bad is almost wholly subject to the discretion of the reader.

The DT article I don’t think per se gives bad advice. Use an outline? Golly I suggest students do that too! Be comprehensive in your lit review about covering all relevant work? Well who can argue with that!

I think an important distinction to make in the advice DT give is the distinction between functional actions and symbolic actions. Functional in this context means an action that makes the article better accomplish some specific function. So for example, if I say you should translate complicated regression models to more intuitive marginal effects to make your results more interpretable for readers, that has a clear function (improved readability).

Symbolic actions are those that are merely intended to act as a signal to the reader. So if the advice is along the lines of, you should do this to pass peer review, that is on its face symbolic. DT’s article is nearly 100% about taking symbolic actions to make peer reviewers happy. Most of the advice doesn’t actually improve the content of the manuscript (or in the most charitable interpretation how it improves the manuscript is at best implicit). In DT’s section Why is it important this focus on symbolic actions becomes pretty clear. Here is the first paragraph of that section:

Literature reviews are important for a number of reasons. Primarily, literature reviews force a writer to educate him/herself on as much information as possible pertaining to the topic chosen. This will both assist in the learning process, and it will also help make the writing as strong as possible by knowing what has/has not been both studied and established as knowledge in prior research. Second, literature reviews demonstrate to readers that the author has a firm understanding of the topic. This provides credibility to the author and integrity to the work’s overall argument. And, by reviewing and reporting on all prior literature, weaknesses and shortcomings of prior literature will become more apparent. This will not only assist in finding or arguing for the need for a particular research question to explore, but will also help in better forming the argument for why further research is needed. In this way, the literature review of a research report “foreshadows the researcher’s own study” (Berg, 2009, p. 388).

So the first argument, a lit review forces a writer to educate themselves, may offhand seem like a functional objective. It doesn’t make sense though, as lit. reviews are almost always written ex post research project. The point of writing a paper is not to educate yourself, but educate other people on your research findings. The symbolic motivation for this viewpoint becomes clear in DT’s second point, you need to demonstrate credibility to your readers. In terms of integrity if the advice in DT was ‘consider creating a pre-analysis plan’ or ‘release data and code files to replicate your results’ that would be functional advice. But no, it is important to wordsmith how smart you are so reviewers perceive your work as more credible.

Then the last point in the paragraph, articulating the need for a particular piece of research, is again a symbolic action in DT’s essay. You are arguing to peer reviewers about the need for a particular research question. I understand the spirit of this, but think back to what function does this serve? It is merely a signal to reviewers to say, given finite space in a journal, please publish my paper over some other paper, because my topic is more important.

You actually don’t need a literature review to demonstrate a topic is important and/or needed – you can typically articulate that in a sentence or two. For a paper I reviewed not too long ago on crime reductions resulting from CCTV installations in a European city, I was struck by another reviewers critique saying that the authors “never really motivate the study relative to the literature”. I don’t know about you, but the importance of that study seems pretty obvious to me. But yeah sure, go ahead and pad that citation list with a bunch of other studies looking at the same thing to make some peer reviewers happy. God forbid you simply cite a meta-analysis on prior CCTV studies and move onto better things.

What should a lit review accomplish?

So again I don’t think DT give bad advice – mostly vapid but not obviously bad. DT focus on symbolic actions in lit reviews because as lit reviews are currently performed in CJ/Crim journals, they are almost 100% symbolic. They serve almost no functional purpose other than as a signal to reviewers that you are part of the club. So DT give about the best advice possible navigating a series of arbitrary critiques with no clear standard.

As an example for this position that lit reviews accomplish practically nothing, conduct this personal experiment. The next peer review article you pick up, do not read the literature review section. Only read the abstract, and then the results and conclusion. Without having read the literature review, does this change the validity of a papers findings? It for the most part does not. People get feelings hurt by not being cited (including myself), but even if someone fails to cite some of my work that is related it pretty much never impacts the validity of that persons findings.

So DT give advice about how peer review works now. No doubt those symbolic actions are important to getting your paper published, even if they do not improve the actual quality of the manuscript in any clear way. I rather address the question about what I think a lit review should look like – not what you should do to placate three random people and the editor. So again I think the best way to think about this is via articulating specific functions a lit review accomplishes in terms of improving the manuscript.

Broadening the scope abit to consider the necessity of citations, the majority of citations in articles are perfunctory, but I don’t think people should plagiarize. So when you pull a very specific piece of information from a source, I think it is important to cite that work. Say you are using a survey instrument developed by someone else, citing the work that establishes that instruments reliability and validity, as well as the original population those measures were established on, is certainly useful information to the reader. Sources of information/measures, a recent piece saying the properties of your statistical model are I think other good examples of things to cite in your work. Unfortunately I cannot give a bright line here, I don’t cite Gauss every time I use the normal distribution. But if I am using a code library someone else developed that is important, inasmuch as that if someone wants to do a similar project they could use the same library.

In terms of discussing relevant results in prior studies, again the issue is the boundary of what is relevant is very difficult to articulate. If there is a relevant meta-analysis on a topic, it seems sufficient to me to simply state the results of the meta-analysis. Why do I think that is important though? It helps inform your priors about the current study. So if you say a meta-analysis effect size is X, and the current study has an effect size much larger, it may give you pause. It is also relevant if you are generalizing from the results of the study, it is just another piece of evidence in addition to the meta-analysis, not an island all by itself.

I am not saying discussing prior specific results are not needed entirely, but they do not need to be extensive. So if studies Z, Y, X are similar to yours but all had null results, and you think it was because the sample sizes were too small, that is relevant and useful information. (Again it changes your priors.) But it does not need to be belabored on in detail. The current standard of articulating different theoretical aspects ad-nauseum in Crim/CJ journals does not improve the quality of manuscripts. If you do a hot spots policing experiment, you do not need to review all the different minutia of general deterrence theory. Simply saying this experiment is likely to only accomplish general deterrence, not specific deterrence, seems sufficient to me personally.

When you propose a book you need to say ‘here are some relevant examples’ – I think the same idea would be sufficient for a lit review. OK here is my study, here are a few additional studies I think the reader may be interested in that are related. This accomplishes what contemporary lit reviews do in a much more efficient manner – citing more articles makes it much more difficult to pull out the really relevant related work. So admit this does not improve the quality of the current manuscript in a specific way, but helps the reader identify other sources of interest. (I as a reader typically go through the citation list and note a few articles I am interested in, this helps me accomplish that task much quicker.)

I’ve already sprinkled a few additional pieces of advice in this blog post (marginal effect estimates, pre-analysis plans, sharing data code), although you may say they don’t belong in the lit review. Whatever, those are things that actually improve either the content of the manuscript or the actual integrity of the research, not some spray paint on your flowers.

Relevant Other Work

CrimRxiv, Alt-Journal Contributions, and Mike Maltz’s Retrospective

As I’m sure followers of mine know, I am a big proponent of posting pre-prints. Spearheaded by Scott Jacques, he has started a specifically criminology focused pre-print server title CrimRxiv. It is still in beta but anyone can contribute a paper if they want.

One of the things me and Scott have been jamming about is how to leverage crimrxiv to make a journal that not only takes advantage of all the goodies on the internet, such as being able to embed interactive graphics or other rich media directly in a journal articles. But to really widen the scope of what ‘counts’ in terms of scholarly contribution. Why can’t things like a cool app, or a really good video lecture you edited, or a blog post illustrating code be put on the same level with journal articles?

Part of the reason I am writing this blog post is that I saw Michael Maltz recently publish a retrospective on his career on Academia.edu. This isn’t a typical journal article, but despite that there is no reason why you shouldn’t share such pieces. So I was able to convince Mike to post A Retrospective Look at My Professional Life to crimrxiv. When he first posted it on Academia.edu here was my response on how Mike (despite never having crossed paths) has influenced my career.


Hi Michael and thank you for sharing,

I’ve followed your work since a grad student at Albany. I initially got hooked on data viz based on Tufte’s book. When I looked for examples of criminologists discussing data viz you were the only one I found. That was sometime around 2010, so you had that chapter in the handbook of quantitative crim. You also had another article about drawing glyphs to illustrate life course transitions I was familiar with.

When I finished my classes at SUNY, I then worked at Troy as a crime analyst while finishing my dissertation. I doubt any of the coffee shops were the same from your time, but I did like walking over to Famous hotdogs for lunch every now and then.

Most of my work at the PD was making time series graphs and maps. No regression, so most of my stats training was not particularly useful. Even my mapping course I took focused on areal data analysis was not terribly relevant.

I tried to do similar projects to your glyph life-courses with interval censored crime data, but I was never really successful with that, they always ended up being too complicated with even moderately large crime datasets, see https://andrewpwheeler.com/2013/02/28/interval-graph-for-viz-temporal-overlap-in-crime-events/ and https://andrewpwheeler.com/2014/10/02/stacking-intervals/ for my attempts.

What was much more helpful was simply doing monitoring metrics over time, simple running means, and then I just inverted the PDF of the Poisson to give error bars, e.g. https://andrewpwheeler.com/2016/06/23/weekly-and-monthly-graphs-for-monitoring-crime-patterns-spss/. Then cases that were outside the error bands signified an anomalous pattern. In Troy there was an arrest of a single prolific person breaking into cars, and the trend went from a creeping 10 year high to a 10 year low instantly in those graphs.

So there again we have your work on the Poisson distribution and operations research in that JQC article. Also sometime in there I saw a comment you made on Andrew Gelman’s blog pointing to your work with error bands for BJS. Took that ‘fan chart’ idea later on and provided error bands for city level and USA level homicide trends, e.g. https://apwheele.github.io/MathPosts/FanChart_NewOrleans.html. Most of popular discussion of large scale crime trends is misguided over-interpreting short term noise in my opinion.

So all my degrees are in criminal justice, but I have been focusing more on linear programming over time borrowing from operations researchers as well, https://andrewpwheeler.com/2020/05/29/an-intro-to-linear-programming-for-criminologists/. I’ve found that taking outputs from a predictive model and then applying a decision analysis to specifically articulate strategies CJ agencies should take is much more fruitful than the typical way academic research is done.

Thank you again for sharing your story and best, Andy Wheeler

Deleted Twitter Account

I’ve decided to delete Twitter. It is for multiple reasons in the end.

Reason 1, I was definitely addicted to it. Checked it quite often during the daytime. Deleting off of my phone (and ditto for email) was a good first step, but I still checked it quite a bit when I was on my personal computer.

Reason 2 — there is a XKCD comic about staying up arguing with people on the internet. I was constantly tempted to do this on Twitter. It is never really worth it. Many of the examples that come to mind I did this — had a comment stream with Pete Kraska the other day about grant funding, and in the past Travis Pratt over pre-prints — Pete/Travis had an ounce of truth in their initial statements, but made sweeping generalizations that don’t describe the majority of people (which included me, hence my urge to respond). While they likely did not intend to say something directly about me, they did so in making general stereotyping comments.

I respect each as scholars, but they just have ill-informed opinions in those cases. You would think criminologists would be less likely to attribute the malice of a few to widespread groups of individuals, but so it goes. No doubt I have bad/wrong opinions all the time as well.

Reason 3, a former colleague the other day was upset I liked a tweet that was a critique of their work. This is just one example, but there are a million different things people could take offense to. I am not interested in even the potential of saying or doing something that would result in a sandbag onslaught I’ve seen several times on Twitter. I of course do not intentionally mean to hurt peoples feelings, but I do not feel like defending minor stuff like that either. Worrying about things like that is just not good for my mental health.

There are of course good things I will be missing out on. I initially joined Twitter to keep up on the news. Between Google Scholar and CrimPapers I can keep up on academic work. (Actual news I should definately not be getting my info from tweets!) But the biggest benefit in the end was there are several internet friends I only met on Twitter and would not have had the opportunity to meet without Twitter.

And of course it was nice to tweet a blog post and get a dozen likes (or say something snarky and get 30). So my work will have less exposure than before, but honestly it was not much to begin with. My last post had more likes (around a dozen) than referrals from Twitter (around half that!) Not like tweeting my blog posts resulted in 1000’s of views, more like a few dozen extra most of the time (and a few hundred extra in the best of times). So I will just continue to write blog posts, and they will have a few less views than before. I wish my blog had bigger reach but it is really just my place for creative output.

I encourage folks to always reach out and send me an email to keep in touch if you are one of my former Twitter friends. Academia can be a lonely place in normal times, and with isolating in the pandemic I can’t even imagine what it would be like without my family. I don’t think my time spent on Twitter was good for my personal well being though in the end, even though it did definitely help me be part of a larger community of colleagues and friends.