Consider the following simple regression model y = ?0 + ?1x1 + u. Suppose Corr(x,u) > 0, Corr(z,x) > 0, and Corr(z,u) < 0. Then, the IV estimator has a(n) _____.?

Moving ________ along the marginal cost curve, the ________

A) upward; opportunity cost of one more unit increases B) upward; marginal cost decreases C) downward; marginal cost increases D) upward; opportunity cost of one more unit does not change E) downward; opportunity cost of one more unit does not change

The median voter model predicts that in a representative democracy _____

a. party platforms will converge to one preferred by the median voter b. successful politicians will emulate the median voter c. third parties will not exist d. successful politicians come from the median political party