Using a discretized measure of academic performance to approximate primary and secondary effects in inequality of educational opportunity.

This study proposes an easy-to-implement approximation for primary and secondary effects in the study of inequality of educational opportunity by discretizing the measure of academic performance. Relative to the widely-used Erikson-Jonsson model, our method is not subject to the potential limitations that are associated with the parametric configurations of the normal distribution of academic performance and the model form restriction for predicting educational choice. Besides, the proposed discretization method can be used to reveal the heterogeneous effect of academic performance on the likelihood of educational transition across the spectrum of performance. Using Monte Carlo simulation and survey data collected in China, we show that our method recovers the results based on the Erikson-Jonsson approach. With another simulation, we illustrate that the Erikson-Jonsson model might produce misleading results if academic performance is not normally distributed. The discretization approach, in contrast, does not suffer from this problem. [ABSTRACT FROM AUTHOR]