Using Equity Risk Premium (ERP) to timing the market

How to calculate ERP:

ERP = (1 / PE - 1 year fixed deposit rate) x 100%

SG Market
ERP > 3.5% good time to invest, ERP < 0.6% stock price overshot;

STI PE: 15.2 (base on FSM 30 Sep data), fix deposite rate: OCBC 0.55%;
current SG market ERP = 6.03%

US Market
ERP > 1.0% good time to invest, ERP < -2.0% stock price overshot.

S&P500 PE: 13.7 (base FSM 30 Sep data), 1 year treasure bill: 0.26% (as  at 1st Oct)
current US maeket ERP = 7.05%