The competition theory promises to greatly enhance our understanding of the factors that lead individuals to engage in ethnic conflict and violence. But to be sure that we are witnessing true competition effects, we need to think carefully about the ways in which studies of ethnic violence, by picking out certain acts from the stream of violence that goes on each day and night, might induce erroneous inferences. This study has suggested the reasons for believing that the case selection difficulties are troublesome and has presented some tentative ways in which to untangle true competition effects from spurious ones. Overall, this study urges some healthy caution in inferring too much from the empirical evidence of competition effects.