School mobility and student achievement in an urban setting

Many studies show negative relationships between school or geographic mobility and school achievement. However. two longitudinal studies show no relationship between mobility and subsequent achievement when prior achievement is controlled. The present study replicates both findings among 764 sixth-grade students in a mobile school district in New York City, with mobility defined by school changes, achievement assessed with standardized tests and age-grade progress, and eligibility for free or reduced price lunches (an economic indicator) controlled. Total mobility was related to sixth-grade achievement when earlier achievement was not controlled, but mobility after third grade was not related to sixth-grade achievement when third-grade achievement was controlled. Some authors suggest that a third variable, such as family background, accounts for both inability and achievement. We provide evidence for a different explanation. Early mobility (prior to third grade) was a more potent predictor of sixth-grade achievement than later mobility. (C) 2000 John Wiley & Sons, inc.