Smoking cessation and health.

This comment questions the conclusion of Jones (1994, 1995) that good health creates an incentive to quit smoking. It is argued that in a cross section, a "stock" of quitters and their present health are observed. Health at the time of cessation is unobserved, and the different time passed since quitting causes an unobserved heterogeneity, masking the true relation between health and smoking cessation. An empirical illustration shows that, at least among the elderly, recent quitters, who provide the most appropriate data on that relation, did so because of poor health.