Accurately describing personnel shortages is difficult in the absence of reliable sources and with problems defining terms. Despite periods when employment opportunities were limited, it appears there has never been a time when the supply of school psychologists was sufficient to meet the demand. Recent personnel shortages follow a period of several decades in which the overall growth of the field surged upward. Among the factors to explain recent shortages is an inverse relationship between professional regulation and the supply of future school psychologists in training. The shortage is predicted to continue indefinitely.