This dissertation explores the effects of agents’ spatial (social or geographic) location on economic outcomes. I study the effects of international migration on public finances and the labor market using the large influx of Venezuelan immigrants to Colombia in recent years. Chapter 1 examines the fiscal impact of immigration and return migration in Colombia from 2013 to 2018 on all levels of government. I draw on several data sources at the National level and state and local governments’ budget executions to construct detailed government receipts and expenditures. Using a static cross-sectional accounting approach, I find that immigrants overall fiscal effect is negative and small (–0.07% of GDP) and is explained entirely by those living in the country for less than a year. I show that the fiscal effect on local budgets is mediated by the ability of governments to raise revenues from their own sources and the size of immigrant inflows relative to the local population. Chapter 2 builds on the previous chapter and revisits the effect of immigration on public finances by accounting for second-order effects. I present a simple framework to explain differences in fiscal contributions among natives and show that immigration can affect natives’ fiscal contributions through three channels: labor displacement, changes in factor prices (labor and capital), and the allocation and cost of providing public services. I test these mechanisms empirically and address self-selection of immigrants into local labor markets using a shift-share instrumental variables approach. The findings suggest that small aggregate effects, for example mediated by the labor market, do not amount to sizeable effects on fiscal contributions of natives. Chapter 3 studies the spatial nature of job referral networks and the effect on immigrants’ labor market outcomes. Using a unique survey data linked to social security records, I find that residence-based labor market networks play an important role in job acquisition for immigrants but don’t seem to improve the quality of the match between firms and workers. Referral networks constrain immigrants’ access to formal jobs through at least two channels: occupational downgrading upon arrival and spatial mismatch.