A recent paper (full PDF here) by Young Hoon Lee and Seung Chan Ahn makes a clever point about occupations in which people are paid for a main activity and a secondary area where success depends on productivity in the main activity. If success in the latter also depends on some other characteristic, people who are well-endowed with that characteristic will invest more in the skills needed to be productive in the main activity: the incentives created by that synergy will spill over to earnings in the main activity.
Their example is the Ladies Professional Golf Association (LPGA). Better-looking golfers get lower scores (perform better) — but only going from average-lookers to the best-looking. Below the average, there’s no effect of differences in looks on tournament scores. That makes sense — you probably won’t get more endorsement opportunities if you’re average-looking instead of bad-looking. Although not golf, one might call this the Sharapova Effect. Are there other labor markets, or other activities, in which a similarly unusual synergy exists??