This paper models the educational process by a system of simultaneous equations. The endogenous variables (educational outputs) are a pupil's achievement, participation in a college preparatory program, need for achievement (aspirations), demonstrated motivation (effort), expectations, self-esteem, belief in his ability to control his environment (fate control), perceived parents' expectations, and perceived teachers' expectations. The 48 exogenous variables include pupil demographic and home characteristic measures, peer group characteristics, and teacher and school characteristics. The sample consists of over 14,000 pupils from the Equality of Educational Opportunity Survey (Coleman Report). The model is estimated by two stage least squares and ordinary least squares. The paper attempts to identify the determinants of each educational output and stresses the causal interrelationships among the outputs. (Author)