My second presentation on distinguishing between the consensual and coercive aspects of duty to obey using natural effects models was much better attended than the first one. You can find the presentation of our work with Jon Jackson, Ben Bradford, and Sarah MacQueen (and the extra slides on the methodology) after the page break.Continue reading “Presentation at the Annual Meeting of the ASC 2.”
This year the Annual Meeting of the American Society of Criminology took place in San Francisco. On Thursday I was asked to present in and chair the ‘Experiments in Policing and Sentencing’ session. I was discussing how block-randomised experiments should be assessed to ascertain that the average treatment effects are unbiased and interpretable. You can find my presentation after the page break. Next week I will also share my second presentation.Continue reading “Presentation at the Annual Meeting of the ASC 1.”
I was honoured to be invited by Kohei Watanabe and Atsushi Tago to give a talk this Wednesday at Waseda University in Tokyo. Upon their request, I was discussing my paper, which is currently under the second round of peer review at the Journal of Quantitative Criminology, from a methodological perspective. Readers of this blog should be familiar with these techniques (for details see the following thread of posts), for which I have already made available the code and the data to encourage future replications. You can find my presentation below, after the page break.Continue reading “Presentation at Waseda University”
I have not been blogging as diligently lately, and one of the reasons for this is that I have been a bit preoccupied with writing resubmissions. As part of this process, I had to revisit the issue of treatment effect consistency which I discussed last summer. This post discusses an alternative way of assessing and quantifying whether treatment effect (in)consistency is present, using methods adopted from meta-analysis.
This post should be considered as an addendum to this previous one that discussed causal mediation analysis with a single mediator. That post ended with the argument that causal evidence could be found that procedural justice indeed mediated the effect of the treatment (previous experiences with the police) towards the outcome (normative alignment with the police). This post will discuss two sensitivity analysis techniques which assess this finding’s robustness to unmeasured confounding. Continue reading “ScotCET and sensitivity analysis for causal mediation analysis with a single mediator”
As discussed in this earlier post, to make meaningful inference from the ScotCET dataset, the focus needs to be shifted to the mediated effect. In such cases, following Baron and Kenny’s (1986) influential article, social scientists usually rely on structural equation modelling and the product method to derive the direct and indirect effects. Nevertheless, this approach has serious limitations that are usually overlooked in the applied literature. Continue reading “ScotCET and causal mediation analysis with a single mediator 2. – Issues with the product method and the sequential ignorability assumption”
This post continues the discussion of the Scottish Community Engagement Trial (ScotCET). In four posts (you can find them here, here, here, and here) I discussed the apparent failure of implementation over the summer. I concluded that despite the unexpected direction of the findings (i.e., those who received the procedurally just treatment had more negative opinion of the police), the treatment effect appeared to be consistent, was not heterogeneous, and thus it could be actually attributed to the research design. Continue reading “ScotCET and causal mediation analysis with a single mediator 1. – Procedural justice and normative alignment with the police”
This final post finishes the discussion of the previous three (you can find them here, here, and here) by looking at treatment effect heterogeneity and design heterogeneity.
Continue reading “Scotcet and implementation failure 4. – Treatment effect and design heterogeneity with a demonstration in R”
This post continues two earlier ones (this one and this one) and assesses the effect consistency across the matched pairs in the ScotCET dataset. Part of the redacted dataset can be downloaded at the bottom of this page which will allow you to carry out the same analysis presented below. Continue reading “ScotCET and implementation failure 3. – Treatment effect consistency in a blocking design with a demonstration in STATA”
How can one evaluate the veracity of the claim made by MacQueen and Bradford (2017), that the treatment effect emerging from the ScotCET RCT is, in fact, attributable to the experimental design, despite the apparent failure of implementation? For this assessment, one needs to discuss some design features of ScotCET. Continue reading “ScotCET and implementation failure 2. – The design features of ScotCET”