Upcoming presentations in seminars, conferences or workshops:


- January 22nd: Sciences Po - Workshop on Immigration, Paris
- February 5th: London School of Economics, London
- February 11th: Universite Paris 1, Paris
- February 16th: FACSEM, Sciences Po, Paris
- February 29th to March 23rd: Visit to UCL/CReAM, London
- March 3rd: Queen Mary University, London
- March 25th: Brown University, Providence
- April 11th: Copenhagen Business School, Copenhagen
- April 15th: University of Copenhagen, Copenhagen

Working papers

Immigration and Wage Dynamics: Evidence from the Mexican Peso Crisis
Latest draft
IZA Discussion Paper No. 8924: link
Find a summary in Vox.

How does the US labor market absorb low-skilled immigration? I address this question using the 1995 Mexican Peso Crisis, an exogenous push factor that raised Mexican migration to the US. In the short run, high-immigration states see their low-skilled labor force increase and native low-skilled wages decrease, with an implied inverse local labor demand elasticity of at least -.7. Internal relocation dissipates this shock spatially. In the long run, the only lasting consequences are for low-skilled natives who entered the labor force in high-immigration years. A simple quantitative many-region model allows me to obtain the counterfactual local wage evolution absent the immigration shock.

Economic Shocks and Internal Migration
Latest draft.
IZA Discussion Paper No. 8840: link

Previous literature shows that internal migration rates are strongly procyclical. This would seem to imply that geographic relocation does not help mitigate negative local economic shocks during recessions. This paper shows that this is not the case. I document that net in-migration rates decreased in areas more affected by the Great Recession. Using various IV strategies that rely on the importance of the construction sector and the indebtedness of households before the crisis, I conclude that internal migration might help to alleviate up to one third of the effects of the crisis on wages in the most affected locations. This is due to a disproportionate decrease in in-migration into those locations rather than an increase in out-migration. More generally, I document that differences in population growth rates across locations are mainly explained by differences in in-migration rates rather than in out-migration rates. I introduce a model to guide the empirical analysis of these facts and to quantify the spill-over effects caused by internal migration.

Minimum Wages and Spatial Equilibrium: Theory and Evidence
Latest draft.
IZA Discussion Paper No. 9460: link
Media coverage: Econ Talk , FEE , Le Journal de Quebec

Often, minimum wage laws are decided at the state or regional level, and even when not, federal level increases are only binding in certain states. This has been used in previous literature to evaluate the effects of minimum wages on earnings and employment levels. This paper introduces a spatial equilibrium model to think about the seemingly conflicting findings of this previous literature. The model shows that the introduction of minimum wages can lead to an increase or a decrease in population depending on the local labor demand elasticity and on how unemployment benefits are financed. The paper provides empirical evidence consistent with the model. On average, increases in minimum wages lead to increases in average wages and decreases in employment. The low-skilled local labor demand elasticity is estimated to be above 1, which in the model is a necessary condition for the migration responses found in the data. Low-skilled workers, who are presumably the target of the policy, tend to leave or avoid moving to the regions that increase minimum wages.

Work in progress

The Labor Market Consequences of Refugee Supply Shocks
with George Borjas. In progress.

Spatial and Social Frictions in the City: Evidence from Yelp
with Donald R. Davis, Jonathan I. Dingel, and Eduardo Morales. In progress.

We employ user-generated data from the social website Yelp to estimate how spatial and social frictions combine to shape consumption choices within cities. Travel time matters for consumption choices, more strongly from work than home. Social frictions also play a large role. Individuals are less likely to visit venues in places demographically different from their own neighborhood. Crime shapes the consumption choices across space differently for men and women. Women, but not men, avoid high- crime areas. We can use our estimates to gauge how much greater these frictions would be if crime were at recent historical peaks and to show how transportation projects would alter the consumption value of a city.

Did Citi Bike Change the Economic Geography of NYC? Evidence from Foursquare
with Donald R. Davis and Jonathan I. Dingel. Preliminary draft available upon request to the institutions I visit for a fly-out.

New York City launched a large bike-sharing program in May 2013. We assess how this change in intracity transportation infrastructure altered consumers' behavior in the city. This is the first analysis of a bike-sharing program in the economics literature. Using location-based social networking data, we exploit temporal and geographic variation to describe how the bike-sharing program altered the geographic distribution of demand. Along with Davis et al. (2014), this is the first use of data from a mobile social media application to measure economic activity. We document an increase in the relative number of visits to venues less proximate to subway stations after the program started. This change in the pattern of visits is found only in areas served by the bike-sharing program. We interpret these facts as evidence that the bike-sharing program disproportionately reduced the cost of traveling to locations not already served by mass-transit infrastructure.

Are there Gains from Immigration Diversity?
Draft available upon request. Awarded the Harriss Prize.

This paper tries to answer a very simple question: are there situations in which we may gain from more immigration diversity? By introducing a model with country specific products we show that, under very plausible circumstances, immigration from various countries of origin might translate into more goods and higher welfare. We also show in our model that natives may gain from this channel in terms of welfare even if they prefer their own products. We then use data for 49 US cities and more than 100 countries of origin to show that a 10% increase in the Immigration Diversity index that we introduce in the model, leads to a 1.1% increase in the number of products available. In order to rule out that there are more products available only because immigrants consume different baskets than natives, we show that a 10% increase in Immigration Diversity at the city level translates into an enlargement of the typical household consumption basket of around 4%. We conclude from this that households potentially gain from immigration. By simulating the model we show that actual levels of immigration in the US cities might account for a 1.5% higher level of welfare than the same cities but without immigrants.

Joan Monras
Assistant Professor
Economics Department and LIEPP
Sciences Po
28, rue de Saint-Pères
75007, Paris