From Tim Fernholz:
….empirical studies suggest that poverty and inequality aren’t behind terror attacks. In the wake of the 9/11 attacks, Alan Krueger, the Princeton economist and future Obama administration official, examined databases of terror attacks to identify trends among the participants. Surprisingly, he found most were well-educated and not poor.
….Later studies confirmed these effects: A 2006 study (pdf) using a broader time range also found that poor countries did not produce more terrorists. By 2007, Krueger had also looked at 311 foreign combatants captured by the US in Iraq, and concluded “that countries with a higher GDP per capita were actually more likely to have their citizens involved in the insurgency than were poorer countries.”