Consider the standard simple regression model y 5 b0 1 b1x 1 u under the Gauss-Markov ^^ cons 5 b0 1 b1inc, the (estimated) marginal propensity to consume (MPC) out of income is simply the slope, b1, Assumptions SLR.1 through SLR.5. The usual OLS estimators b0 and b1 are unbiased for their respec- tive population parameters. Let b