This week in my Sports Econ class I'll be talking about, among other things, the draft as a measure to promote competitive balance. I will also talk about the perverse incentives that certain draft structures may cause, one being tanking: the incentive to lose games to improve draft status. This year the NBA is taking a close look at tanking (links are in the original).
The NBA’s current lottery system incentivizes less-than-blessed franchises to do all they can to do as little as possible in order to be in the best position to draft someone like, say, Victor Wembanyama.
The league has tried various initiatives to curb the scourge that is tanking — something NBA commissioner Adam Silver addressed after a question by team employees with the Phoenix Suns recently — a franchise that seemingly has very little chance of such a worry.
Beck Taylor and Justin Trogdon looked at this very thing in a paper published 20 years ago.
The focus of tournament models has been rank‐order compensation schemes whereby participants receive higher payments for higher relative performance, either incrementally or winner‐takes‐all. Our research focuses on a unique tournament that offers rewards for both winning and losing, specifically the National Basketball Association’s regularly scheduled season of games. We examine three NBA seasons to determine whether team performance responded to changes in the underlying tournament incentives provided by the NBA’s introduction and restructuring of the lottery system to determine draft order. Our results yield strong evidence that NBA teams are more likely to lose when incentives to lose are present.
Taylor and Trogdon (TnT) looked at three NBA seasons, 1983-84, 1984-85, and 1989-90. In 1984-85, the NBA had a strict reverse-order draft. In 1984-85, non-playoff teams' draft order was by lottery meaning they had equal chances of having the number one pick. In 19z89-902, the NBA used a weighted lottery meaning all non-playoff teams had a chance to pick first, but the worst team had the best chance, the second worst team had the second best chance, etc. etc. .
After controlling for other factors*, TnT found that non-playoff teams' probability of losing was 2.5 times as great as playoff teams in the strict reverse-order draft, 2.2 times as likely to lose as playoff teams in the weighted lottery, and no less nor more likely to lose under the lottery system. So TnT found evidence consistent with tanking. What will the NBA find this year?
*The other factors are team WPCT, opponent WPCT, home game for the team, away game for the team, whether the team or the opponent had clinched a playoff berth, and whether the team or the opponent had been eliminated from earning a playoff berth.