Is there any *real* difference between paying a kid for getting good grades and paying her for good athletic performance/effort? And further, are either or both 'bad' for kids?
If you’re gonna pay them for either, I suppose grades would be the better choice.
Unless they’re gonna turn pro & make money with sports, excelling at education seems to be the way to go for securing any kind of future.
Offering a cash reward for every “A”
(or whatever) could be used as a comparison to illustrate how smarts can earn them money as an adult.
If you want to educate them about
realistically making money with sports, teach them how to read a football pool.