A successful tit-for-tat strategy leads to

Which of the following statements is true?

A) Models help economists to explain the past, but do not help in predicting the future. B) The scientific method used by economists is based on idealism and not empiricism. C) Testing with data enables economists to distinguish between good models and bad models. D) Models that economists use are perfect replicas of reality.

Which of the following will cause an increase in the marginal product of capital (MPK)?

A) a decrease in the quantity of labor in use B) an increase in labor productivity C) a decrease in the quantity of capital in use D) all of the above E) none of the above