<p>Urban economics has long relied on the assumption of perfect mobility, where workers relocate in direct response to differences in local economic conditions. In contrast, recent evidence on internal migration reveals persistent frictions and a strong distance gradient. This paper develops a static general equilibrium model of migration in which workers differ in their aversion to relocation. We distinguish geographic and non-geographic factors behind relocation decisions, modeling the former as a continuous variable that workers perceive logarithmically. The framework shows how large cities disproportionately attract workers with low relocation aversion and high tolerance for long-distance migration. A counterfactual exercise further demonstrates that the removal of distance-related frictions would flatten the city-size distribution, with smaller cities experiencing a proportionally larger reduction in agglomeration intensity than larger ones.</p>