Q1: y = β0 + β1x + β2z + u Suppose we are particularly interested in estimating β1 but we only have information on a random sample for (yi, xi), i = 1, . . . , n. Under which conditions would it be correct to estimate the model y = β0 +β1x+u? Q2: The file VOTE1.dta contains information on Congressional campaign expenditures for the U.S. House of Representatives in 1988. For each of the 173 two-party races we know the percentage of votes received by candidate A (voteA), the logarithm of campaign expenditures (in thousands of US dollars) for both candidate A (lexpendA) and candidate B (lexpendB) and, consequently, the share of total expenditure accounted for by candidate A (shareA). voteA = β0 + β1lexpendA + β2lexpendB + u Test the hypothesis H0 : β1 = −β2 versus the alternative H1 : β1 ̸= −β2, and describe why this might be of interest.