Recently economics researchers have suggested that most persons respond to economic incentives in choosing when to retire, although a small percentage exit the labor force because of deteriorating health. Although recent and proposed changes in the social security system are likely to have only small effects on retirement behavior, larger impacts could ensue from altering the incentives implicit in many private pension plans. Little is known about the transition process that follows the end of career jobs and precedes retirement: this represents an important area for future research.