Some of Gov. Terry Branstad’s campaign pledges — to reduce the cost of government by 15 percent, raise family incomes by 25 percent, create 200,000 jobs and have the best schools in the nation — may be mutually exclusive, economists say. Andrew Cannon, a researcher for the non-partisan Iowa Policy Project , said it will be hard to reduce the cost of government by 15 percent without affecting the state’s quality of education, for instance.