[영문]In the presence of frictions, firms adjust their capital structure infrequently. As a consequence, in a dynamic economy the leverage of most firms is likely to differ from the qqqquot;optimumqqqquot; leverage at the time of readjustment. This paper explores the empirical implications of this observation. I use a calibrated dynamic trade-off model to simulate firms' capital structure paths. The results of standard cross-sectional tests on these data are consistent with those reported in the empirical literature. In particular, the standard interpretation of some test results leads to the rejection of the underlying model. Taken together, the results suggest a rethinking of the way capital structure tests are conducted.