NBA Age Eligibility, Literature Review Example

In the “Effect of Early Entry into the NBA”, Nick Sugai analyzes the decision of high school players to forego college (both basketball and the putative education), in favor of playing in the National Basketball Association. Indeed after a raft of talented high-school players went directly into the NBA, the league erected a minimum age of 19 for draft eligibility. Sugai analyzes how “on-the-job-performance”, that is foregoing college opportunities to enter the NBA affect a player’s performance. Although the study generally suffers from the malady of low statistical power, he finds that less skilled players (defined as a lower-ranked player) generally do worse in the NBA. Thus, they are helped by the minimum age requirement in that they might receive additional training in college basketball that might be more beneficial to their development. He finds for those higher-ranked players, however, that the minimum age requirement has little efficacy; that is, higher ranked players have a “neutral or positive effect” when entering the NBA. These players are arguably better off entering the NBA in order to hone their skills.

Rodenberg and Kim (2012) also examine the question of how the NBA’s minimum age requirement affects player performance. The authors’ data set includes all players selected in the first round of the NBA draft from 1989 to 2000. The authors utilize a censored normal regression estimator for each of the three dependent variables: 1) Average minutes played per game; 2) Player efficiency rating; 3) All-star game appearances.

The analysis found that players drafted a younger age had more successful NBA careers, on average. This effect was consistent across the three dependent variables: players that chose to enter the NBA played more minutes than those that didn’t, earned a higher efficiency rating than their college peers, and appeared in more NBA All-Star games.

The authors posit that their data analysis challenges the uniformity of the NBA’s age eligibility rule and the “one-size fits all” policy. The authors cite three main reasons for this conclusion: 1) NBA teams’ draft performance shows they are able to choose those players that will excel in the league; 2) The minimum age limit may hurt players, particularly as there is limited evidence for “late-blooming” NBA players. 3) There is a notable dearth of evidence that individuals that play in college for an attenuated time period (e.g., one year) have better performance than those players who directly enter the NBA.

Berri, Brook, and Fenn assume a different angle in their analysis: how does the reverse order draft and informational asymmetries affect a team’s draft choices? The authors’ data set is composed of college basketball players selected in the NBA draft from 1995 to 2009. Draft position is the dependent variable of the study; the predictor variables selected were: 1) player performance in college; 2) player height; 3) a ratio of player’s height to the position played in the NBA; 4) Player’s age. The analysis found that the three independent variables all had a statistically significant impact on where a college basketball player was ultimately selected in the draft; however, the player’s performance in college, particularly scoring, had the biggest impact on a player’s ultimate draft position. Thus, the authors conclude while a player may focus on many different aspects of their game (including rebounds and assists), any player that wants to be drafted in the upper echelon of players would be wise to focus on scoring vis-à-vis other potential metrics.

Works Cited:

Berri, David, Brook, Stacy, Fenn, Aju. From college to the pros: predicting the NBA amateur draft. Journal of Product Analysis. 2011.

Rodenberg, Ryan and Kim, Jun Woo. Testing the On-Court Efficacy of the NBA’s Age Eligibility Rule. Journal of Quantitative Analysis in Sports. Manuscript

Sugai, Nick. The Effect of Early Entry in the NBA. Amherst College Senior Thesis.