Refer to Figure 7.1. At what level of output are average total cost, average cost, average fixed cost and marginal cost increasing?

In principle, trade can make a nation better off, because the gains to the winners exceed the losses to the losers

a. True b. False Indicate whether the statement is true or false

To obtain an estimator that reproduces the fixed effects estimates on the time-varying explanatory variables, _____.

A. ?one must check whether the time-demeaning allows one to interpret the estimates B. ?one must check whether time-constant variables can be included in the fixed effects C. ?one must be able to interpret the time variations D. ?one must be careful in constructing the time averages