This is my version of an equity valuation model that is very similar to the "Fed Model" and the one used by Art Laffer for many years. It's based on the assumption that the best measure of corporate profits is to be found in the National Income and Product Accounts. It capitalizes those profits using the interest rate on 10-year Treasury bonds, and compares that theoretical measure of value to the actual value as measured by the S&P 500 index.
Based on this model, stocks have NEVER been so cheap. That's another way of saying that this market is priced to the expectation that we will be in a depression that will cause massive bankruptcies and gargantuan losses all over the world. (World stock market capitalization yesterday was down 55% from its year-ago high.)
You've got to be a real pessimist to not like stocks at these levels.