摘要：This paper examines the relationship between risk,concentration and the exercise of market power by banking institu tions. The authors use monthly balance-sheet and interest rate data for the Colombian banking system from 1997 to 2006. The evidence shows that,in the face of high risk,banks transfer a larger share of risk to customers through higher intermediation margins. The result suggests that risk acts as a "collusion” device for banks:while high concentration is not enough to have collusion,the true effects of high market concentration on interest rates’ mark-ups emerge when the system is under stress.
