An age limit, such as the NFL's, has been tossed around by the NBA. The success of the NFL in withstanding the court challege from Maurice Clarrett made serious consideration by the NBA a near certainty. Jermaine O'Neil has raised the spector of racism behind such a move. While there may be race-based consequences, the motivations are summed up not by black and white but by green. A statement by Grant Hill in the New York Times and cited in an article by Jason Whitlock on ESPN.com gets to the heart of the motivation
"I always thought that it was the purpose of the union to protect its members, not potential members ...I think if anyone gets left out, it's the older players, guys who put equity into this league, card-carrying members paying their dues to the union. I would hope they would be protected."
If only the motives of all interest groups were so transparently stated! Yahoo!'s Dan Wetzel suggests another motivation, one for owners, growing out of their desire reduce the uncertainty of acquiring younger players. This motive is a little more subtle. On the one hand, the "average" owner does not gain or lose competitiveness relative to other teams if all get lucky or make mistakes on occassion. However, the relevant decision horizon is probably much shorter than the period of time long enough for all of the luck-mistakes to balance out. Over the short haul, increased uncertainty may expose owners to large, asymmetric risks. I'm not totally sold, but it's possible. Alternatively, owner support may be as simple as the ubiquitous desire to reduce uncertainty in decisions.