Extreme value processes feature in any economic model in which agents receive a number of draws from some distribution and we examine the behavior of the maximum in the limit as the number of draws becomes large. This paper asks: Do the average outcomes of such processes change when different agents receive a different number of draws? To answer this, we allow the number of draws an agent receives from the underlying distribution (e.g. of productivities, ideas, or utility shocks) to be given by a search technology, which reflects heterogeneity in the expected number of draws across different types of agents. We derive a new class of extreme value distributions that generalize the three standard distributions (Fréchet, Gumbel, Weibull) by incorporating heterogeneity across agent types. We generalize a result from Gabaix, Laibson, Li, Li, Resnick, and de Vries (2016) regarding extreme value outcomes and consider applications to aggregate productivity, markups, and social networks.

@article{Mangin_2026_EVT,
  title={Extreme value theory with heterogeneous agents},
  author={Mangin, Sephorah},
  journal={Econometrica (forthcoming)},
  year={2026}
}

We introduce consumer choice into a search-theoretic model of monetary exchange. In contrast to standard search models featuring bilateral meetings, consumers can meet multiple sellers and choose a seller with whom to trade. Market power is endogenized through competitive search and it is influenced by the degree of consumer choice. We consider the effects of greater consumer choice on both market power and the welfare cost of inflation. Surprisingly, we find that greater consumer choice can have a nonmonotonic effect on market power. At lower levels of consumer choice, an increase in the degree of consumer choice tends to increase firms' market power, while the opposite is true at higher levels. When we calibrate the model to U.S. data, we find that despite greater consumer choice having a positive effect on welfare overall, it can also amplify the negative welfare effects of inflation, making it significantly more costly.

@article{Mangin_Bajaj_inflation,
  author = {Sephorah Mangin and Ayushi Bajaj},
  title = {Consumer choice, market power, and inflation},
  journal = {European Economic Review (forthcoming)},
  year = {2026}
}

We examine the effect of expected competition on markups in a random utility model where the number of competing firms may differ across consumers. Firms observe consumers' utility shocks and set prices using personalized pricing. We derive a precise condition under which the expected markup across consumers can be represented by a simple expression involving consumers' expected utility and the expected demand. This delivers a general condition under which greater expected competition is price-increasing. Whether this condition holds depends on the distribution of utility shocks, consumers' outside option, the expected number of competing firms, and the distribution of the number of firms competing for each consumer.

@article{Mangin_2024_RAND,
  author = {Mangin, Sephorah},
  title = {When is competition price-increasing? The impact of expected competition on prices},
  journal = {The RAND Journal of Economics},
  volume = {55},
  number = {4},
  pages = {627-657},
  year = {2024}
}

When is entry efficient in markets with search and matching frictions? This paper generalizes the well-known Hosios condition to dynamic environments where the expected match output depends on the market tightness. Entry is efficient when buyers' surplus share is equal to the matching elasticity plus the surplus elasticity (i.e. the elasticity of the expected match surplus with respect to buyers). This ensures agents are paid for their contribution to both match creation and surplus creation. For example, vacancy entry in the labor market is efficient only when firms are compensated for the effect of job creation on both employment and labor productivity.

@article{Mangin_Julien_2021_JET,
  author = {Sephorah Mangin and Benoît Julien},
  title = {Efficiency in search and matching models: A generalized Hosios condition},
  journal = {Journal of Economic Theory},
  volume = {193},
  pages = {105208},
  year = {2021}
}

The labor share fluctuates over the business cycle. To explain this behavior, we develop a novel model featuring direct competition between heterogeneous firms to hire workers. This simultaneously endogenizes both average match productivity and the division of output between workers and firms. In existing matches, wages partly reflect labor market conditions at the time of hiring. A positive TFP shock therefore reduces the aggregate labor share, making it counter-cyclical. However, greater competition and lower unemployment increase labor's share among new firms. As more firms enter, the aggregate labor share rises and eventually overshoots its initial level, as in the data.

@article{Mangin_Sedlacek_2018_JME,
  title = {Unemployment and the labor share},
  author = {Sephorah Mangin and Petr Sedlácek},
  journal = {Journal of Monetary Economics},
  volume = {94},
  pages = {41-59},
  year = {2018}
}

This paper develops a search-theoretic model of the labor market in which heterogeneous firms compete directly to hire unemployed workers. This process of direct competition simultaneously determines both the expected match output and workers' effective bargaining power. The framework delivers a unified aggregate production and matching technology, and firms are paid both productivity rents and matching rents. Both the curvature of the endogenous production technology and the distribution of output between workers and firms are influenced by properties of the underlying firm productivity distribution, particularly the tail index (a measure of tail fatness). For example, if the firm productivity distribution is Pareto, the labor share is decreasing in its tail index if the value of matching rents is not too high.

@article{Mangin_2017_JET,
  title = {A theory of production, matching, and distribution},
  author = {Mangin, Sephorah},
  journal = {Journal of Economic Theory},
  volume = {172},
  pages = {376-409},
  year = {2017}
}

@article{Mangin_Julien_2017_EL,
  author = {Sephorah Mangin and Benoît Julien},
  title = {Efficiency of job creation in a search and matching model with labor force participation},
  journal = {Economics Letters},
  volume = {150},
  pages = {149-151},
  year = {2017}
}

@article{Mangin_Zenou_2016_EL,
  author = {Sephorah Mangin and Yves Zenou},
  title = {Illegal migration and policy enforcement},
  journal = {Economics Letters},
  volume = {148},
  pages = {83-86},
  year = {2016}
}

@article{Mangin_et_al_2009_CJE,
  author = {Sephorah Mangin and Benoît Julien and John Kennes and Ian King},
  title = {Directed search, unemployment, and public policy},
  journal = {Canadian Journal of Economics},
  volume = {42},
  number = {3},
  pages = {956-983},
  year = {2009}
}