This paper develops a model encompassing both matching and hedonic models, studies its properties, and provides identification and estimation strategies. We bring the model to data on internal migration in China to answer the question raised in the title. We estimate the migration surplus of singles and couples and the marital surplus of natives and, using counterfactuals together with our identification strategy, quantify the marrying-up and the work effects of migration. Results show that, for floating (resp. permanent) migrant women married with urban men, the marrying-up effect is positive but 3.5 (resp. 5) times smaller than the work effect. However, as these migrant women enter the urban marriage market, they generate equilibrium marrying-up effects for all men and women by changing the relative supply of women on both the rural and urban marriage markets. These effects can be large relative to the work effect of migration for some types of migrants (floating migrant women married with a permanent migrant man and floating migrant women married with a floating migrant man) and represent about 13% of the equilibrium utility of urban native men.