中文摘要
移民通过劳动力市场和公共预算两条渠道影响本国居民，但这两条渠道通常被分开研究。我们在一个包含搜寻与匹配摩擦、按技能区分的累进劳动税、资本税与公共产品的一般均衡模型中将二者结合起来，并利用2015–2019年17个经合组织（OECD）国家的数据进行校准。移民流入增加一个百分点对本国居民福祉的影响，其符号与大小在各国间存在差异，取决于移民的技能构成、移民与本国的工资差距、当地失业率以及税收累进性。对于与2019–2024年到达移民技能构成相符的流入，17个经济体中有14个的本国居民福祉上升，且在多数情形下两个技能群体均通过不同渠道获益。低技能本国居民主要从税前收入提高中获益，其驱动因素是就业创造及与高技能移民的互补性；高技能本国居民则主要从劳动税负下降中获益。因此，评估移民政策需要将劳动力市场渠道与财政渠道联合建模：单独任一渠道都无法完整呈现谁获益以及为何获益。
Abstract
Immigration affects natives through both labor markets and public budgets, yet these channels are usually studied separately. We combine them in a general-equilibrium model with search-and-matching frictions, skill-specific progressive labor taxes, capital taxation and public goods, calibrated to 17 OECD countries over 2015-2019. The welfare effect on natives of a one-percentage-point increase in immigrant inflows varies in sign and size across countries, hinging on immigrants' skill mix, immigrant-native wage gaps, resident unemployment, and tax progressivity. For inflows matching the skill composition of 2019-2024 arrivals, native welfare rises in 14 of 17 economies, and in most cases both skill groups gain, through different channels. Lower-skilled natives gain mainly from higher pre-tax earnings, driven by job creation and complementarity with skilled immigrants; higher-skilled natives gain mainly from lower labor-tax burdens. Evaluating immigration policy thus requires modeling labor-market and fiscal channels jointly: either channel alone gives an incomplete picture of who gains and why.