Authors of intermediate microeconomics textbooks devote relatively more space to imperfectly competitive markets than can be justified by their relative occurrence in actual markets. This gap has persisted for at least 40 years, even with an almost complete turnover of authors between the decades of the 1960s and the 2000s. This portrayal gives students a distorted view of the presence of market imperfections throughout the economy. It appears that many authors have strong beliefs that noncompetitive behavior permeates most markets even though concentration statistics fail to support these views. Authors may overly stress noncompetitive industry analyses to enlarge their advocacy role in public policy discussions and analyses of firm behavior in antitrust cases and consulting. (Contains 5 tables and 17 endnotes.)