Precocity in the NBA

The NBA's age eligibility rule will be one of many issues that the league and union negotiate in the coming weeks. A large number of published papers have looked at the legality of the NBA age rule. Examples are here, here, and here.

Research has also touched on the efficacy of the minimum age rule. Mike McCann's oft-cited article looked at the issue from an economic perspective, with a particular emphasis on opportunity costs. Earlier this week, Peter Newman and Dean Oliver of ESPN blogged about whether age is a factor in the NBA draft. Newman and Oliver concluded, in relevant part, that: "...the trend is that a younger, highly drafted player will have more success than an older one." Such conclusion is consistent with my findings. I ran an OLS regression with age as my variable of interest and included a number of control variables found elsewhere in the literature. Across each dependent variable, age was a statistically significant predictor of on-court success. The working paper's conclusion is as follows:

Precocity and basketball are intertwined. If the current NBA age rule was in place prior to 2005, some of the best players in the league (Kevin Garnett, Kobe Bryant, LeBron James and Dwight Howard) during the past 15 years would have been initially ineligible. We find evidence that the younger a player is when he first enters the NBA labor pool the more successful he is likely to be. There is no systematic evidence of any success among “late bloomers.” Our findings cast doubt on the long-term on-court efficacy of the NBA’s age rule, although the recent imposition of the league’s age policy, coupled with certain off-court considerations that may be relevant, caution against any conclusive determination regarding the rule’s effectiveness (and necessity). Likewise, limitations stemming from the censored data argue against a more definitive position on such issue.