Terrorist Use of the 1/N Heuristic in Attack Method Choice

A simple rule of thumb or heuristic that may be used in place of complete optimisation is a 1/N heuristic. That is, choose equally across alternatives. Terrorist groups select from among attack method categories. In doing so, we ask whether they apply a 1/N heuristic or whether a more sophisticated decision-making process may be a more suitable starting point for understanding terrorist attack method choice when combinations of alternatives is feasible. Ultimately, we conclude that the stability that is evident in the proportions that each attack method constitutes in the aggregate of combinations formed by all terrorist groups since 1970 is reflective of the structure predicted by Phillips’ (2009) application of the Markowitz mean-variance utility analysis.