"Many resources have been spent on the war on drugs in Colombia under Plan Colombia. By most available measures, however, the results have not been the expected ones. The amount of cocaine reaching consumer countries remains relatively stable seven years after the initiation of Plan Colombia, and the price of cocaine at different stages has not risen. Thus, the general impression is that policies aimed at reducing the amount of drugs reaching consumers by curtailing their production and trafficking have been relatively ineffective. Despite the substantial resources invested in this war, no independent evaluation of the antidrug policies implemented under Plan Colombia had been done until now. Our principal aim in the research agenda summarized in this chapter is to fill this gap."