According to classical works on social stratification, status homogamy can be regarded as an indicator of the "openness" of society. In contrast to previous approaches, this article treats marriage choice as a multidimensional phenomenon and makes a distinction between ascriptive- and achievement-oriented characteristics. Ascriptive status homogamy is measured by the similarity of spouses with respect to their fathers' occupational class, while the achieved dimension of status homogamy is measured by the similarity of spouses' educational attainment. Multivariate log-linear models are used to explore the relative importance of these factors for the choice of a spouse, and the article tests the hypothesis that there has been a transition from ascription to achievement in patterns of marriage selection. This study first demonstrates empirically that previously conducted synthetic cohort analyses of educational homogamy suffer from selection biases and then, using the Occupational Change in a Generation (OCG...