The Paradox of Openness: Educational Openness and the Reproduction of Social Inequality

Educational systems differ in how easily students advance through their educational careers -a characteristic we call “openness.” Although the effects of other features of educational systems -tracking, selectivity, and standardization- have been extensively studied, the impact of openness on inequality remains underexplored. We define openness as a continuous institutional dimension shaped by regulatory reforms (e.g., timing of tracking, entry exams) and by public funding policies that lower financial barriers. Using detailed retrospective life-history data for Spanish cohorts born 1900–1973, we estimate lower-secondary completion probabilities by parental background across three regimes: elite, transitional, and mass systems. Our theory predicts and our results confirm an inverted-U relationship: initial, modest increases in openness widen attainment gaps as advantaged families exploit relaxed barriers, whereas further liberalization eventually narrows those gaps once access is widespread. This non-linear trajectory reflects distinct group dynamics. During the transitional phase, privileged students disproportionately benefit, while high-ability youths from disadvantaged backgrounds gain only marginally. Only after substantial reductions in both institutional and economic hurdles does completion equalize across backgrounds. Contrary to what could be expected, our study demonstrates that incremental openness reforms can exacerbate inequality before universal access is reached.