Céline Poilly

Chercheuse ,  Aix-Marseille Université , Faculté d'économie et de gestion (FEG)

Macroéconomie, économie du travail et économie internationale
Poilly
Statut
Professeur des universités
Domaine(s) de recherche
Macroéconomie
Thèse
2008, University of Cergy-Pontoise
Téléchargement
CV
Contact
celine.poilly[at]univ-amu.fr
+33(0)4 13 55 25 67
Adresse

AMU - AMSE
5-9 Boulevard Maurice Bourdet, CS 50498
​13205 Marseille Cedex 1

Site
https://sites.google.com/view/celinepoilly
Résumé Higher trade policy uncertainty has recessionary effects on U.S. states. To demonstrate this, we first build a novel empirical measure of regional trade policy uncertainty based on the volatility of national import tariffs at the sectoral level and on the sectoral composition of imports in U.S. states. We find that a state that is more exposed to an unanticipated increase in tariff volatility suffers from a larger drop in real GDP and employment than the average U.S. state. We then build a two-region open-economy model and find that the precautionary saving behavior is the main driver of the recession, although this effect is reinforced by high exposure to import tariffs. The feedback effect resulting from trade connections with the Foreign country primarily influences the persistence of these dynamics. ✩ The National Bureau of Economic Research has provided financial sponsorship to make this article open access and had no influence or involvement over the review or approval of any content. ✩✩ This article is part of a special issue entitled: ISOM 2024 published in Journal of International Economics. ★ We are grateful to the organizers of the 2024 NBER International Seminar on Macroeconomics (ISoM), Jordi Galí and Kenneth West as well as our discussants, Andrea Raffo and Joseph Steinberg, the Editor Linda Tesar and the participants for their insightful comments. The comments and remarks provided
Mots clés Uncertainty shocks, Tariffs, Regional effects, Precautionary behavior
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Résumé This short paper provides U.S. state-level evidence regarding the effects of trade policy uncertainty on the labor market. We show that a higher exposure to trade policy uncertainty generates a contraction in total hours worked at the state level. The extensive margins of labor is the primary margin of employment adjustment. State-level employment is more strongly impacted by trade policy uncertainty in goods-producing industries, and more particularly in the durable goods industry. States which are more specialized in goods industries, when they face higher uncertainty, tends to postpone hiring by more, which explains the drop in total employment.>
Mots clés Uncertainty shocks, Tariffs, Labor Market
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Résumé We rationalize the observed short-run differences in corporate and long-term government bond yields in an financial-accelerator model with frictions that restrict changes in portfolio shares. We estimate the model on quarterly data for the Euro Area from 1999 to 2019, and show that the portfolio friction parameter is positive and significant. Portfolio frictions not only generate a time-varying wedge between the two returns that fits the data, but also raise the volatility of return differentials, and the precautionary motive of savers. As a result, the macroeconomic effects of uncertainty shocks are amplified by portfolio frictions.
Mots clés Financial Accelerator, Uncertainty shocks, Portfolio frictions
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Résumé We assess the role of demand noise (excessive optimism or pessimism about demand) together with supply noise (excessive optimism or pessimism about supply). To do so, we propose a methodology to decompose business cycles into supply, demand, supply noise and demand noise shocks, using a structural vector autoregression model. Key to our identification of both supply noise and demand noise is the use of sign restrictions on survey expectation errors about output growth and about inflation. We show that demand-related noise shocks have a negative effect on output and contribute substantially to its fluctuations. Monetary policy and private information seem to play a key role in the transmission of demand noise shocks.
Mots clés SVAR with sign restriction, Noise shock, Information friction, Business cycle
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Résumé In the aftermath of the U.S. financial crisis, both a sharp drop in employment and a surge in corporate cash have been observed. In this paper, based on U.S. data, we argue that the negative relationship between the corporate cash ratio and employment is systematic, both over time and across firms. We develop a dynamic general equilibrium model where heterogenous firms need cash and external liquid funds in their production process. We analyze the dynamic impact of aggregate shocks and the cross-firm impact of idiosyncratic shocks. We show that external liquidity shocks generate a negative comovement between the cash ratio and employment, as documented in the data.
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Résumé The paper investigates how endogenous markups affect the extent to which policy reforms can influence international competitiveness. In a two-country model where trade costs allow for international market segmentation, we show that endogenous pricing-to-market behavior of firms acts as an important transmission channel of the policies. By strengthening the degree of competition between firms, product market deregulation at home leads to a reduction in domestic markups, which generally leads to an improvement in the international competitiveness of the Home country. Conversely, the power of competitive tax policy to depreciate the real exchange rate is dampened, as domestic firms take the opportunity of the labor tax cut to increase their markups. The variability of markups also affects the normative implications of the reforms. This indicates the importance of taking into account endogenous pricing-to-market behavior when intending to correctly evaluate the overall effects of the reforms.
Mots clés Endogenous Markups, Fiscal reform, Endogenous firm entry, Product market deregulation, Pricing-to-market, Exchange rate, Pricing-to-market, Endogenous Markups, Endogenous firm entry, Product market deregulation, Exchange rate, Fiscal reform
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Résumé Bilateral bargaining between a multiple-worker firm and individual employees leads to overhiring. With a concave production function, the firm can reduce the marginal product by hiring an additional worker, thereby reducing the bargaining wage paid to all existing employees. We show that this externality is amplified when firms can adjust hours per worker as well as employment. Firms keep down workers’ wage demands by reducing the number of hours per worker and the resulting labor disutility. Our finding is particularly relevant for European economies where hours adjustment plays an important role.
Mots clés Intrafirm bargaining, Hours, Employment, Overhiring
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Résumé Recessions are often accompanied by heightened uncertainty. We look at the effect of endogenous uncertainty on aggregate demand and its implications for monetary policy. We enrich a non-linear New-Keynesian model with imperfect noisy information, where the precision of signals is pro-cyclical. The endogenous uncertainty channel amplifies aggregate demand effects through precautionary saving. Ultimately, it can even reverse sign of the output-gap response to a supply shock. Monetary policy can eliminate both pricing and information-induced inefficiencies by closing the output gap. Based on U.S. household income forecast errors data, we estimate a sizable and significant degree of pro-cyclicality in the precision of signals.
Mots clés Precautionary saving, Aggregate demand, Imperfect information, Endogenous uncertainty
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Résumé Endogenous uncertainty acts as an aggregate-demand amplification mechanism of supply shocks. Using U.S. data, we first stress that taking into account time-varying macroeconomic uncertainty leads to a significantly stronger recession and less inflationary pressures, in response to a TFP shock. In addition, we show empirically that households' misperception increases during recessions. To rationalize these findings, we build a noisy-information New-Keynesian model where the precision of signals increases with economic activity. Pro-cyclical precision of information gives rise to an amplified precautionary saving behavior. A fullfledged model parametrized by using consumer-based forecast errors generates a demandlike recession of supply shock.
Mots clés Uncertainty, Imperfect information, Keynesian supply shocks
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Résumé Higher uncertainty about trade policy has recessionary effects in U.S. states. First, this paper builds a novel empirical measure of regional trade policy uncertainty, based on the volatility of national import tariffs at the sectoral level and the sectoral composition of imports in U.S. states. We show that a state which is more exposed to an unanticipated increase in tariff volatility suffers from a larger drop in real output and employment, relative to the average U.S. state. We then build a regional open-economy model and we argue that the transmission channels of uncertainty shocks, in particular the precautionary-pricing channel, are magnified in regions that feature the highest import share and a strongest export intensity. Furthermore, we show that an expansionary monetary policy may amplify the regional divergence since it worsens the recession in the most-exposed region to trade policy uncertainty.
Mots clés JEL classification E32, E52, F41 Uncertainty Shocks, JEL classification E32 E52 F41 Uncertainty Shocks Regional Effects Precautionary Pricing Monetary Policy, Monetary policy, Precautionary Pricing, Regional effects, Uncertainty shocks
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Résumé Higher uncertainty about government spending generates a persistent decline in the economic activity in the Euro Area. This paper emphasizes the transmission channels explaining this empirical fact. First, a Stochastic Volatility model is estimated on European government consumption to build a measure of government spending uncertainty. Plugging this measure into a SVAR model, we stress that government spending uncertainty shocks have recessionary, persistent and humped-shaped effects. Second, we develop a New Keynesian model with financial frictions applying to a portfolio of equity and long-term government bonds. We argue that a portfolio effect-resulting from the imperfect substitutability among both assets-acts as a critical amplifier of the usual transmission channels.
Mots clés Government spending uncertainty, Stochastic volatility, Portfolio adjustment cost
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Résumé The paper investigates how endogenous markups affect the extent to which policy reforms can influence international competitiveness. In a two-country model where trade costs allow for international market segmentation, we show that endogenous pricing-to-market behavior of firms acts as an important transmission channel of the policies. By strengthening the degree of competition between firms, product market deregulation at home leads to a reduction in domestic markups, which generally leads to an improvement in the international competitiveness of the Home country. Conversely, the power of competitive tax policy to depreciate the real exchange rate is dampened, as domestic firms take the opportunity of the labor tax cut to increase their markups. The variability of markups also affects the normative implications of the reforms. This indicates the importance of taking into account endogenous pricing-to-market behavior when intending to correctly evaluate the overall effects of the reforms.
Mots clés Exchange rate, Product market deregulation, Fiscal reform, Endogenous firm entry, Pricing-to-market, Endogenous Markups
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Résumé We assess theoretically and empirically the consequences of demand misperceptions. In a New Keynesian model with dispersed information, agents receive noisy signals about both supply and demand. Firms and consumers have an asymmetric access to information, so aggregate misperceptions of demand by the supply side can drive economic fluctuations. The model’s predictions are used to identify empirically fundamental and noise shocks on supply and demand. We exploit survey nowcast errors on both GDP growth and inflation, fundamental and noise shocks affecting the errors with opposite signs. We show that demand-related noise shocks have a negative effect on output and contribute substantially to business cycles. Additionally, monetary policy plays a key role in the transmission of demand noise.
Mots clés Business Cycles, Information frictions, Noise shocks, SVARs with sign restrictions
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Résumé Intra-firm bargaining between a multiple-worker firm and an individual employee leads to overhiring. Taking advantage of the decreasing returns to scale in employment, the firm can reduce the marginal product by hiring an additional worker, thereby reducing the bargaining wage paid to all existing employees. We show that this externality is amplified when firms can adjust hours per worker as well as employment. Hours are too low at the steady state. This misallocation of labor leads to sizeable welfare losses. Our finding is important for economies in which hours adjustment play an important role as it does in many Euro Area countries.
Mots clés Distortions, Intra-firm bargaining, Optimal monetary policy
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