LAUSR

authors never specify the number of demolitions analyzed. We are confident they only analyzed 6638 demolitions, which falls significantly short of the “over 10,000 buildings” threshold they claim (see Table 1). Finally, the failure to account for 5938 pre-Q2 2014 demolitions means that many of the block groups designated as “pre-treatment” (less than 6 demolitions) are miscategorized. This, again, calls into question the validity of their results because if pre-Q2 2014 demolitions were accounted for, they would have found that an additional 191 block groups received at least 6 demolitions by the end of Q3 2015. When those omitted demolitions are considered, the number of treated block groups increases from 343 to 534. This likely has implications for their findings, particularly their claim that threshold effects were observed. In our view, this study has particularly meaningful flaws, and it misleads readers into believing that (a) Detroit’s largescale demolition program began in Q2 2014, (b) they analyzed over 10,000 demolitions, and (c) there is a point of diminishing returns beyond 12 demolitions within a block group. While it is true that demolitions accelerated in Q2 2014, to claim the program began in April 2014 is incorrect. In fact, the number of omitted demolitions in this study is almost equivalent to the number they include in their analyses. Unlike most readers, we have worked with the City of Detroit’s demolition data for over 2-years and have intimate knowledge about the program. As such, we urge researchers involved in this work to be more careful methodologically and more intentional in understanding the nature and history of policies like this one. It is possible these missteps can be explained by the authors, but the fact remains that their methodological and substantive errors should not be overlooked. Jay and colleagues’ study assessing the impact of the City of Detroit’s demolition program on firearm violence and illegal drug violations represents one of the first attempts to understand the nexus between blight removal and criminal activity. While novel in its focus, it suffers from serious methodological shortcomings and substantive inaccuracies that require attention. First, the authors’ understanding that Detroit’s largescale demolition program began in Q2 2014 (p. 627) is mistaken and consequently undermines the veracity of the study’s conclusions. Between January 1, 2010 and March 31, 2014—the 39 months prior to the authors’ study period—the City of Detroit razed 5938 buildings, which, at that point, already represented the largest demolition intervention of any city in the history of the United States. Not accounting for nearly 6000 demolitions in their analyses is undoubtedly problematic for Jay et al.’s (2019) paper because it means that their models are mis-specified in unknown ways. Second, even after carefully reading their manuscript, it remains unclear how many demolitions were accounted for in their study period (Q2 2014–Q3 2015). Confusingly, the authors write, “By the end of 2016, the period we study here, the city had demolished over 10,000 buildings” (p. 627, emphasis added). Other than this vague reference, the