pzoch

Piotr
Żoch

Piotr received his PhD in Economics from the University of Chicago. His main research interests are macroeconomics and monetary economics, in particular macroeconomic theory and macro-finance.

Personal website: pzoch.com

Opublikowane | Published

  • Financial intermediation and aggregate demand: A sufficient statistics approach | Review of Economic Studies

    We provide a unified framework to study how the financial sector affects the transmission of macroeconomic policies, such as monetary and fiscal policies, and asset purchase programs. Our framework nests models of financial intermediation with various microfoundations and allows for rich household heterogeneity. The financial sector supplies liquidity by issuing liquid assets to finance illiquid capital. The elasticities of liquidity supply with respect to returns are sufficient statistics that summarize how the financial sector determines responses to policy through asset markets. This asset market channel has a strong effect on output when liquidity supply is inelastic. We apply our approach to study the relative effectiveness of policies targeting the financial sector versus households. In commonly used setups, aggregate output responses differ by orders of magnitude due to implicit assumptions about the elasticities. Our estimates of the liquidity supply elasticities for the U.S. economy imply a modest effect through the asset markets and a stronger effect of targeting households.

    Piotr
    Żoch
  • The distributional effects of bailouts | Federal Reserve Bank of St. Louis REVIEW

    This article examines the distributional effects of government bailouts using a heterogeneous agent New Keynesian model with financial intermediation frictions. We analyze government equity injections to financial institutions financed by debt issuance, capturing essential features of bailout policies during financial crises. When calibrated to match key features of the U.S. economy, bailout policies are expansionary and reduce inequality through general equilibrium effects operating primarily via aggregate demand stimulation and increased labor income rather than direct wealth effects. Equity injections increase the financial sector’s capacity to intermediate capital, leading to higher capital prices, increased investment, and substantial aggregate demand increases. This improves labor market conditions that benefit lower-income households more than wealth effects benefit the wealthy. The result is reduced wealth and consumption inequality, demonstrating that bailouts can simultaneously achieve macroeconomic stabilization and inequality reduction.

    Piotr
    Żoch
  • Some unpleasant markup arithmetic: Production function elasticities and their estimation from production data | Journal of Monetary Economics

    The ratio estimator of a firm's markup is the ratio of the output elasticity of a variable input to that input's cost share in revenue. This note raises issues that concern identification and estimation of markups using the ratio estimator. Concerning identification: (i) if the revenue elasticity is used in place of the output elasticity, then the estimand underlying the ratio estimator does not contain any information about the markup; (ii) if any part of the input bundle is either used to influence demand, or is neither fully fixed nor fully flexible, then the estimand underlying the ratio estimator is not equal to the markup. Concerning estimation: (i) even with data on output quantities, it is challenging to obtain consistent estimates of output elasticities when firms have market power; (ii) without data on output quantities, as is typically the case, it is not possible to obtain consistent estimates of output elasticities when firms have market power and markups are heterogeneous. These issues cast doubt over whether anything useful can be learned about heterogeneity or trends in markups, from recent attempts to apply the ratio estimator in settings without output quantity data.

    Piotr
    Żoch
  • Macroprudential and monetary policy rules in a model with collateral constraints | Gospodarka Narodowa

    We compare welfare and macroeconomic effects of monetary policy and macroprudential policy, in particular targeting loan-to-value (LTV) ratios. We develop a DSGE model with collateral constraints and two types of agents. In this setup, we study seven potential policy rules responding to credit growth and fluctuations in prices of collateral. We show that monetary policy responding to deviations of collateral prices from their steady state value results in the highest level of social welfare. It is also useful in stabilizing output and inflation. Macroprudential policy using LTV ratio as the instrument is dominated in terms of output and inflation stability by the interest rate rules. If interest rate rules are not available, the LTV ratio can be used to improve welfare, but gains are small.

    Piotr
    Żoch

W toku | Work in progress

  • Optimal asset market operations

    We characterize governments' optimal responses to asset market disturbances across a broad class of models with financial frictions. We show that the Ramsey plan can be achieved by a policy rule targeting a specific relationship between asset returns, regardless of the underlying disturbances. This relationship is determined by asset supply and demand elasticities that can be estimated empirically with standard identification strategies. Absent financial frictions, the optimal policy stabilizes spreads across all assets. However, in the presence of financial frictions, the optimal rule prescribes time-varying spreads to facilitate financial intermediation. We apply our framework to study the optimal design of asset purchase and lending programs, as implied by key empirical estimates of asset supply and demand elasticities.

    Piotr
    Żoch
  • Demographic transition and the rise of wealth inequality

    We analyze the contribution of rising longevity to the increase in wealth inequality in the U.S. over the past seventy years. To do so, we construct an overlapping generations (OLG) model with multiple sources of inequality, carefully calibrated to the data. Our key finding is that improvements in old-age longevity have a substantial impact on wealth inequality, accounting for approximately half the effect of income inequality, which has been the focus of much of the existing literature. In contrast, the impact of tax changes is relatively minor. The contribution of rising longevity is expected to continue driving wealth inequality upward in the coming decades.

    Krzysztof
    Makarski
    Joanna
    Tyrowicz
    Piotr
    Żoch
  • Markups, labor market inequality and the nature of work

    We demonstrate the importance of distinguishing between the traditional use of labor for production, versus alternative uses of labor for overhead, marketing and other expansionary activities, for studying the distribution of both factor income and labor income. We use our framework to assess the impact of changes in markups on the overall labor share and on labor income inequality across occupations. We identify the production and expansionary content of different occupations from the co-movement of occupational income shares with markup-induced changes in the labor share. We find that around one-fifth of US labor income compensates expansionary activities, and that occupations with larger expansionary content have experienced the fastest wage and employment growth since 1980. Our framework can rationalize a counter-cyclical labor share in the presence of sticky prices and can be used to study the distributional effects of demand shocks, monetary policy and secular changes in competition.

    Piotr
    Żoch