The general objective of teacher tenure laws was well stated by Hunter to be sound and stable teaching profession . . . compatible with the educational interests of society, the welfare and progress of pupils, and justice to teachers.1 Do such laws in fact lead toward or away from this objective ? The present study seeks a partial answer to this question. Specifically, it seeks to determine, in order to infer the causal effects of teacher tenure laws, whether such laws are accompanied by perturbations in supply and demand. Review of the literature.?Almack found that the average term of service in Portland, Oregon, was nearly 2.5 years greater under the per manent tenure law than before its passage.2 The National Education Association's Committee of One Hundred, under Hunter as chairman, found the average annual turnover in 13 cities, having a population of 100,000 or more and located in States having tenure laws, to be only four percent; but the average annual turnover in 18 cities of com parable size, in States not having tenure laws, was six percent. The author continued :