A book publisher has a monopoly on the hardcover edition of a particular book, for which the demand curve is as pictured. Wanting to boost sales, the publisher drops the price from $20 to $15. In the graph, this change appears as a movement from point P1 to point P2.

Use the area tool to draw the region representing theprice effect.(The combined result of theprice effectand theoutput effectwill determine whether the publisher's move was a good idea.)