Furthermore, in 1986, the U.S. had one of the lowest effective marginal corporate tax rates for equity-financed investments in machinery and industrial structures in the U.S., and now we have one of the highest.

FORBES: # 9 The 1986 reform hit tax shelters and arbitrage hard

That paper suggested companies shouldn't think of their capital structures as fixed--say 40% debt, 60% equity.

FORBES: Dow Jones Interactive

In the meantime, buy-out shops are already trying to figure out ways to adapt by changing the structures of their deals, says Steve Puccinelli of Investcorp, a private-equity firm.

ECONOMIST: Private-equity firms battle to keep their tax perks