FICA Regs on NQDC

[Guest halka]

Trying to understand the regs related to returns on a "predetermined actual investment." It appears one could use the S&P 500 as the PAI and could adopt it for 5 prospective years. If so, is there any "averaging" or carryback or forward of years in which returns were less than S&P?? If in Yr 1, S&P returned +10% and NQDC +5% and in Yr 2 S&P +8% and NQDC +13%, is there any offset between Yrs 1 & 2? Also, if S&P is -10% and NQDC is -6% is there 4% "excess earnings" subject to FICA??

Thanks for your comments.