Summary of Labor Economics: Migration and Job Turnover

## Introduction Migration refers to the movement of people across locations (within a country or between countries) driven by economic opportunities, family decisions, costs, and preferences. This guide breaks migration concepts into digestible pieces, uses examples, and highlights key models and empirical patterns. ## Key concepts and the standard migration model ### What the standard migration model says - People move when the expected present value of living in the destination exceeds that of the origin after accounting for costs. > **Definition:** The standard migration model: a framework where individuals compare the present value of lifetime earnings and amenities in origin and destination, subtract moving costs, and choose the location that maximizes utility. - Present value calculation uses discounted future incomes and utilities. > **Definition:** Present value: the sum of future incomes or utilities discounted to today: if annual income is $y_t$ and discount factor each year is $\beta^{t}$, the present value is $\sum_{t=0}^{T} \beta^{t} y_t$. ### Components that affect migration decisions - Expected wage differences across locations - Moving (financial and psychic) costs - Preferences for amenities, family ties, and social networks - Uncertainty about actual labor-market outcomes after moving Did you know that migrants often face large nonmonetary costs such as leaving family and adapting to new social norms that can outweigh apparent wage gains? ## Internal migration (within countries) ### Typical patterns - Younger workers migrate more than older workers because they have more future years to recoup moving costs. - More educated workers migrate more because returns to their skills vary more by location. - Family structure matters: married households, couples with children, and high-education couples behave differently. > **Definition:** Tied mover: a person who moves because the household moves even though that person would prefer to remain. Tied stayer: a person who remains because the household stays even though that person would prefer to move. ### Family and household decisions - Households make joint present-value comparisons; a move occurs if household utility/joint present value rises. - A household move can create both tied movers and tied stayers: one spouse benefits directly while the other bears costs. Practical example: Crystal (Chicago wage $500$, Tampa wage $550$, moving cost $300$) and Amelia (Chicago wage $200$, Tampa wage $1000$, moving cost $600$). Joint Chicago earnings $700$, joint Tampa earnings $1550$, joint moving cost $900$. The household compares net gains: $1550 - 900 - 700 = -50$? (Careful: compute net gain as destination earnings minus origin earnings minus moving cost.) ### Factors that generate return and repeat migration - Misestimation of job opportunities or amenities in the first destination - Better-than-expected job offers later elsewhere - Realization that moving costs or psychic costs differ from expectations Fun fact: Return and repeat migration are common because initial moves often involve uncertainty; migrants update beliefs and respond rationally. ## Self-selection of immigrants (the Roy model) ### What self-selection means - Selection describes which types (by skill) choose to migrate. > **Definition:** Positive selection: migrants are, on average, higher-skilled than the source-country average. Negative selection: migrants are, on average, lower-skilled than the source-country average. - The Roy model links skill-specific returns across origin and destination to selection patterns: people who gain most from moving (in expected earnings) choose to move. ### Intuition and implications - If skill returns are higher in the destination for high-skilled workers, migration tends to be positively selected (high-skilled move). - If returns favor low-skilled workers, migration can be negatively selected. - Changes in migration costs and returns alter selection: highe