Migration's impact spans various social dimensions, including demography, sustainability, politics, economy and gender disparities. Yet, the decision-making process behind migrants choosing their destination remains elusive. Existing models primarily rely on population size and travel distance to explain flow fluctuations, overlooking significant population heterogeneities. Paradoxically, migrants often travel long distances and to smaller destinations if their diaspora is present in those locations. To address this gap, we propose the diaspora model of migration, incorporating intensity (the number of people moving to a country) and assortativity (the destination within the country). Our model considers only the existing diaspora sizes in the destination country, influencing the probability of migrants selecting a specific residence. Despite its simplicity, our model accurately reproduces the observed stable flow and distribution of migration in Austria (postal code level) and US metropolitan areas, yielding precise estimates of migrant inflow at various geographic scales. Given the increase in international migrations due to recent natural and societal crises, this study enlightens our understanding of migration flow heterogeneities, helping design more inclusive, integrated cities.

翻译：迁移的影响涉及人口学、可持续性、政治、经济和性别差异等多个社会维度。然而，移民选择目的地的决策过程仍然难以捉摸。现有模型主要依赖人口规模和旅行距离来解释流动波动，忽略了显著的人口异质性。矛盾的是，如果移民在某个目的地有同族散居人群，他们往往会长途跋涉前往那些规模较小的目的地。为弥补这一不足，我们提出了移民散居模型，该模型整合了强度（迁移至某国的人数）和同配性（在该国内的居住地选择）。我们的模型仅考虑目的地国现有散居人口的规模，从而影响移民选择特定居住地的概率。尽管模型简单，但它准确再现了奥地利（邮政编码层面）和美国大都市地区观测到的稳定移民流动与分布，在不同地理尺度上提供了对移民流入量的精确估计。鉴于近期自然和社会危机导致的国际移民增加，本研究深化了对移民流动异质性的理解，有助于设计更具包容性、融合性的城市。