Meanwhile, contractors have relatively bleak expectations for a number of public sector market segments. For example, 40 percent of contractors report they expect the public building market to shrink in 2013, while only 18 percent expect that market to expand — a net difference of -22 percent. Similarly, 37 percent of contractors report they expect the K-12 school construction market will shrink this year with only 20 percent expecting that market to grow — a net of -17 percent. Contractors have mixed views about the public infrastructure market, however. Contractors.