Questions from Quant ?? testing, standard, always, hypothesis, chance

ramdabom

Questions from linear regression:

1. When we say regression forecasts are unbiased do we always need b0=0 and b1=1? I thought sum of residual being 0 is enough to mean forecasts are unbiased. (see Example 11: Evaluating Economic Forecasts 2 in Reading 11)

2. When we testing the null hypothesis that b1=1.0, if SSE (standard error of estimate) decreases t value increases and null hypothesis rejection chance increases. Though it comes mathematically but I thought low SSE shouldn't make b1 significantly different from 1.0. Can anybody tell me why low SSE makes b1 significantly different from 1.0? (see Reading 11 section 3.5: Hypothesis testing)

Nurul Hai