Robert Pape’s work on suicide terrorism — notably, this book — has attracted a lot of attention (e.g., here). He was also — and here is a fact I did not know until today — an advisor on Ron Paul’s campaign team.
Pape analyzes data on all 188 suicide terror attacks between 1980 and 2001. He concludes that almost all of these attacks shared one common feature: they targeted a country believed to be a foreign occupier. This, not religious extremism, was the motivation of those who committed these suicide attacks.
Now a soon-to-be-published paper argues that Pape’s data cannot support that conclusion. The paper is here, authored by Scott Ashworth, Joshua Clinton, Adam Meirowitz, and Kristopher Ramsay. In short, they argue, the problem is this. To know whether X causes suicide terrorism, we need to know how the propensity to use suicide terrorism varies with X. That is, we not only need data on when suicide terrorism occurs, we need data on when suicide terrorism does not occur — i.e., when groups choose other tactics besides suicide terrorism. Analyzing only instances when suicide terrorism occurred is not sufficient.
Ashworth et al. conclude:
bq. The data Pape collects do not speak to the correlates of suicide terror, and the policy conclusions he advocates cannot be justified by appealing to the data he collects.