These results push back against the stereotype of a basketball player driven by an intense desire to escape poverty. In “The Last Shot,” Darcy Frey quotes a college coach questioning whether a suburban player was “hungry enough” to compete against black kids from the ghetto. But the data suggest that on average any motivational edge in hungriness is far outweighed by the advantages of kids from higher socioeconomic classes.
What are these advantages? The first is in developing what economists call noncognitive skills like persistence, self-regulation and trust. We have grown accustomed to hearing about the importance of these qualities for success in school, but players in team sports rely on many of the same skills.
To see how poor noncognitive skills can derail a career in sports, consider the tragic tale of Doug Wrenn. Mr. Wrenn was born five years before Mr. James, also to a single mother in a poor neighborhood. He, too, was rated among the top basketball players in high school. But Mr. Wrenn, unlike Mr. James, was notoriously uncoachable and consistently in legal trouble. He was kicked off two college teams, went undrafted, bounced around lower leagues, moved in with his mother and was eventually imprisoned for assault.
The second relevant advantage of a relatively prosperous upbringing is height. The economist Robert W. Fogel has demonstrated the impact of improved early life nutrition on adult height over successive generations. Poor children in contemporary America still have substandard nutrition, holding back their development. They have higher infant mortality rates and lower average birth weights, and recent research has found that poverty in modern America inhibits height. In basketball, the importance of every inch is enormous. I estimate that each additional inch almost doubles your chances of making the N.B.A.
The N.B.A.’s changing demographics may also reflect the advantages of growing prosperity. Even casual fans will have noticed the difference the past 30 years have made: In 1980, fewer than 2 percent of N.B.A. players were foreign-born; now more than 20 percent are.
