Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
The theories of human capital and internal labor markets are used to analyze teacher mobility. With data for the San Diego school system, we find that (1) since teaching assignments within school systems do not differ in terms of salary, internal mobility of teachers is governed by such nonpecuniary differences as student socioeconomic status (SES). As a result, (a) new teachers tend to be placed in low SES schools; (b) teachers tend move toward and to stay in higher SES schools. (2) As a consequence, higher SES schools have faculties with relatively greater experience and educational attainment. The correlation between these teacher characteristics and student achievement reflects, therefore, mutual causation.