Jan H. Pierskalla and Florian M. Hollenbach have a new paper (via the Monkey Cage) arguing that cell phone coverage makes collective action easier, and that includes making political violence easier. Good for them. A post-doc and a PhD candidate in the APSR looking at an interesting problem, relevant to the “Did Twitter cause the Arab Spring” question, and using novel data (particularly novel on the independent variable side and using the up-and-coming UCDP Georeferenced Event Dataset on the dependent variable side). Their study uses data from Africa, but its larger implications seem apparent.
The question you have to ask yourself is whether cell phone coverage makes it more likely that “an event” will be recorded in the dataset, a dataset derived from “print, radio, and television news reports from regional newswires, major and local newspapers, secondary sources, and expert knowledge….” If not, then data is missing in a biased way. The cell phones are not increasing violence through collective action but rather through greater reporting on violence that was happening irrespective of cell phones. Depending on the model specification, cell phones might be associated with a 50% increase in reports of a violent event (involving at least one death), from a baseline of about 1% to 1.5%. (Other models report larger effects.) That bump seems plausible to me from cell phone reporting alone, without any collective action effect. I do not know what the situation is like in Africa, but in India and Pakistan it is routine for political violence in the countryside to be under-reported. I assume the effect is multiplied when it is in the countryside, without cell phone coverage, and one has to walk 4 miles to make a phone call about it.
These researchers are aware of this problem and they try to control for it. You can read their discussion on page 6 (particularly footnote 13) and see if you think they resolve it. Also, they are aware that cell phones cover areas with more people and more people are likely to be associated with more violence. I’m a little more comfortable with their strategy for controlling for population (see page 8), though who knows if population’s effect on violence is linear? The fact that when they conduct a robustness check of using a logarithmic transformation of population it weakens their findings for the effect of cell phone coverage “somewhat” (p. 8, footnote 18) is worrisome to me.