Detail

7. Once again, recall that the slope of a PPF is the Opportunity Cost of one good in terms of the other. Since PPF C is a straight line, the Opportunity Cost of good 1 in terms of good 2 is constant no matter what mix of good 1 and good 2 is currently being produced. On PPF B the slope is different at every point. The cost, in terms of good 2, for producing more good 1 is higher the more good 1 is already being produced along PPF B.