3 Association of Research Libraries Research Library Issues 295 — 2018 Demographic Trends in the ARL Library Professional Population: An Overview Steven Mandeville-Gamble, University Librarian, University of California, Riverside In the following articles, Stanley Wilder explores a series of trends shaping the professional population of Association of Research Libraries (ARL) member institutions. For 30 years, research libraries have been talking about the “greying of the profession” and the inevitable mass turnover in professional staff that was sure to result from this demographic trend. But year after year, that mass retirement had not played out. By digging into the ARL Salary Survey data, Wilder makes significant observations of how the demographic trends are unfolding and how geopolitical and economic forces outside of the boundaries of the profession itself, namely the economic collapse of 2008–2009, encouraged many library professionals to delay retirement. Wilder’s research shows that this mass trend towards delayed retirements significantly distorted the distribution of professionals by age, away from a natural distribution curve to one that was highly shifted towards the higher end of the age spectrum. But the logical end point of that distorted distribution curve has finally been reached, and the mass wave of retirements is even more momentous as a result. Simultaneously, Wilder’s research underscores a harsh reality: research libraries have dramatically reduced the overall size of their staff since the beginning of the Great Recession, which has resulted in far fewer positions available to younger colleagues than has been true historically. So while the waves of mass retirement are happening, this is a moment in time when there are far fewer positions available overall than even a decade ago. This is particularly troubling for a profession that has been discussing the need for dramatic demographic shifts to ensure that the profession reflects the demographics of its larger community. As Wilder’s research makes clear, the profession as a whole and the members of