Congress is now investigating to see if the NBA is acting legally in enforcing its age requirement. I understand the NBA's desire to improve its product by lessening its exposure to untested talent, but there is something unAmerican about denying opportunity to someone who is skilled enough to earn a living using his skills - even if its just for one or two years.
I have the answer to quandry. Incentivize staying in school. It sounds simple, and it is (hey, I thought of it, how complicated could it be). Rookie salaries are predetermined by order of the CBA. Let's say the first pick overall is slotted to get $5 million per year for 3-years.
The NBA should say "if you are a college grad when you sign your contract, or 22, you are entitled to 100% of that amount.
If you are a senior (but have not graduated) or 21, you are entitled to 90%. A junior or 20, 80%. a sophomore or 19, 70%, younger than that, 50%.
Now when Blake Griffin is considering whether to come out after his sophomore year, first he knows that going to class (and thus entering the NBA as a junior instead of a sophomore) is work $500,000 per year for 3 years (plus the 4th year option). A kid considering coming out of high school, or Rick Rubio coming from overseas is contemplating making the jump for $2.5 million per year, or if he waits two years, maybe coming in for $4 million (if he enters as a junior or 20 year old).
Now, you don't want to give the teams a cost-savings reason to pick a younger guy (so that drafting a kid out of high school saves them 50% as opposed to drafting a senior). So split the the deducted percentage between charity (hey, its the NBA, where caring happens) and the NBDL.
a) The Garnetts and Bryants and LeBrons can come out (they easily make up the difference in incentives),
b) the players are rewarded for maturing OUTSIDE the NBA (as opposed to Psycho-T, or Glen Davis, or Joakim Noah, all of whom lost money by staying in college when they were drafted than they would have been had they made the leap),
c) the NBA gets Congress off their backs and increased revenue for its minor leagues,
d) charity receive money from the benevolent (ha ha) business of basketball. Everybody wins.
Don't everyone applaud at once. I have written this before, but I will continue to promote this idea until someone with some clout hears/repeats it.