8.a. In this example, Patrick is better off by $0.50 because he was willing to pay $2.50 but paid just $2.00. Jill is better off by $0.75 because she would have accepted $1.25 but Patrick paid her $2.00. So the total value created is the additional value to Patrick ($0.50) plus the additional value to Jill ($0.75), which sums to $1.25.

b. The value added for Jason is $1,500, which is the difference between the minimum price he would have accepted ($6,000) and the price he received ($7,500). The value added for Hillary is $2,500, which is the difference between the maximum price she would have paid ($10,000) and the price she actually paid

($7,500). In total, $1,500 + $2,500 = $4,000 in new value was created through the exchange.