Free-operant behavior is more resistant to change when the rate of reinforcement is high than when it is low. The usual partial reinforcement extinction effect, demonstrating greater resistance to extinction after intermittent than after continuous reinforcement, seems to contradict this generalization. However, most free-operant extinction data are reported as response totals, which confound the initial levels of responding and the rate at which responding decreases over the course of extinction. A reanalysis shows that after extended training, the slope of the extinction curve is shallower after continuous reinforcement than after intermittent reinforcement, suggesting greater rather than less resistance to change. These results, which hold for both independent-groups and within-subject comparisons, support the general finding that resistance to change of free-operant behavior is a positive function of the rate of reinforcement. This generalization does not, however, hold for discrete-trial performance. I discuss some consequences of these analyses for applications of behavioral research results.