SSRN-Market Evaluation of Off-Balance Sheet Financing: You Can Run But You Can't Hide by Steve Lim, Steven Mann, Vassil Mihov
Super short version: using operational leases as a means of keeping debt off the balance sheet may fool bond rating agencies, but it does not seem to fool the bond market.
Lim, Mann, and Mihov (all from TCU) find that attempts to hide debt (in the form of operating leases--the most popular form of off balance sheet financing) may "be useful in maintaining higher debt ratings" but "it does not fool the market, because bond yields reflect off-balance sheet obligations...in the same manner as balance sheet does." I love it when the market gets it right! :)