Knowledge that Transforms

This paper develops a model to study the macroeconomic implications of supply chain disruptions with three key ingredients: (i) a firm-level network of customized supplier–customer links that generate relationship-specific productivity gains; (ii) bargaining over these relationship-specific surpluses; and (iii) an extensive margin of adjustment, whereby firms decide to form or sever relations with suppliers and customers. We establish equilibrium existence and uniqueness, provide characterization results, and present a number of comparative statics that show how supply chains and aggregate output respond to shocks. We also show that equilibrium supply chains are inefficient and exhibit an inherent fragility: small shocks can lead to discontinuous changes in output, even though the efficient allocation is always continuous in the same shocks. We explore several macroeconomic implications of this fragility.

Meritocracies aspire to reward hard work and promise not to judge individuals by the circumstances into which they were born. However, circumstances often shape the choice to work hard. I show that people’s merit judgments are “shallow” and insensitive to this effect. They hold others responsible for their choices, even if these choices have been shaped by unequal circumstances. In an experiment, U.S. participants judge how much money workers deserve for the effort they exert. Unequal circumstances disadvantage some workers and discourage them from working hard. Nonetheless, participants reward the effort of disadvantaged and advantaged workers identically, regardless of the circumstances under which choices are made. For some participants, this reflects their fundamental view regarding fair rewards. For others, the neglect results from the uncertain counterfactual. They understand that circumstances shape choices but do not correct for this because the counterfactual—what would have happened under equal circumstances—remains uncertain.

We study demand estimation in a large auction market. In our model, a dynamically evolving population of buyers with unit demand and heterogeneous and privately known preferences for a finite set of differentiated products compete in a sequence of auctions that occur in discrete time. We define an empirically tractable equilibrium concept in which bidders behave as though they are competing with the stationary distribution of opposing bids, characterize bidding strategies, and prove existence of equilibrium. Having developed this demand system, we prove that it is non-parametrically identified from panel data. We extend the model to consider a random coefficients demand system akin to workhorse demand models in industrial organization, and show that this too is non-parametrically identified. We apply the model to estimate demand and show how large sellers can exercise market power by using persistent reserve price policies, which induce higher bids and, therefore, revenues. Our analysis highlights the importance of both dynamic bidding strategies and panel data sample selection issues when analysing these markets.

We study the distributional effects of asset ownership on price informativeness in a general equilibrium model. The model features investors (oligopolists) with different degrees of price impact and abilities to learn about individual asset payoffs from private and price signals, and a competitive fringe that only learns from asset prices. We show that price informativeness is non-monotonic in the oligopolists’ aggregate size, decreasing in the sector’s concentration and in the size of the passive sector. We further show that the size effect can be decomposed into a learning channel capturing investors’ quality of private signals and an information pass-through channel measuring the sensitivity of investors’ trades to private signals, with the latter one being the primary source of variation in price informativeness relative to the size distribution.

Economists have widely endorsed pricing CO2 emissions to internalize climate change-related externalities. Doing so would significantly affect coal, the most carbon-intensive energy source. However, U.S. coal markets exhibit an additional distortion: the railroads that transport coal to power plants can exert market power. This article estimates how coal-by-rail markups respond to changes in coal demand. I identify markups in a major intermediate goods market using both reduced-form and structural methods. I find that rail carriers reduce coal markups when downstream power plant demand changes due to a drop in the price of natural gas (a competing fuel). My results imply that decreases in coal markups have increased recent U.S. climate damages by $11.9 billion, compared to a counterfactual where markups did not change. Incomplete pass-through would likely erode the environmental benefits of an incremental carbon tax, shifting the tax burden towards upstream railroads. Still, a non-trivial tax would likely increase welfare.

We propose a theory that analyzes how a workers’ asset holdings affect their job productivity. In a labor market with uninsurable risk, workers choose to direct their job search trading off productivity and wages against unemployment risk. Workers with low asset holdings have a precautionary job search motive, they direct their search to low productivity jobs because those offer a low risk at the cost of low productivity and a low wage. Our main theoretical contribution shows that the presence of consumption smoothing can reconcile the directed search model with negative duration-dependence on wages, a robust empirical regularity that the canonical directed search model cannot rationalize. We calibrate the infinite horizon economy and find this mechanism to be quantitatively important. We evaluate a tax financed unemployment insurance (UI) scheme and analyze how it affects welfare. Aggregate welfare is inverted U-shaped in benefits: the insurance effect UI dominates the incentive effects for low levels of benefits and vice versa for high benefits. In addition, when UI increases, total production falls in the economy while worker productivity increases.

We show that mortgage recourse systems, by discouraging default, magnify the impact of nominal rigidities. They cause deeper and more persistent recessions. This mechanism can account for up to 31% of the recovery gap during the Great Recession between the U.S., mostly a non-recourse economy, and Spain, a recourse economy. General equilibrium effects explain most of the differences between mortgage systems. With recourse, highly indebted homeowners dramatically cut consumption in a crisis, and account for a larger share of the aggregate consumption decline. However, without recourse, mortgages would be more expensive for riskier households, and homeownership rates would be lower.

Do firms adjust wages in response to changes in their own demand level or to changes in competitive pressure from rival employers? We study how exporters adjust wages in response to unexpected product demand shocks during the 2008–9 Great Recession. Using rich data on Portuguese firms’ pre-recession export shipments, we measure firm-level shocks to export demand during the Recession. We show that shocks constructed at the firm level are not necessarily firm-specific and can be decomposed into a common component affecting all producers in a product market and an idiosyncratic component affecting individual firms within markets based on the locations of their pre-recession customers. We demonstrate that while both components impact firms’ output and their workers’ wages, the common component spills over from firms to their labour market rivals, whereas the idiosyncratic component does not. We find that 10–15% of firms’ idiosyncratic demand passes through to their employees’ wage growth with no effect on retention rates, implying significant dependence of wages on noncompetitive quasi-rents. Moreover, we find that wages respond primarily to shifts in internal labour demand when labour markets are thin, but they respond more to competition from other employers when labour markets are fluid. These results indicate that employers’ ability to set wages hinges on the underlying competitiveness of the labour market.

Rich behavioural biases, mistakes, and limits on rational decision-making are often thought to make equilibrium analysis much more intractable. We establish that this is not the case in the context of one-sector growth models such as Ramsey–Cass–Koopmans or Bewley–Aiyagari models. We break down the response of the economy to a change in the environment or policy into two parts: the direct response at the given (pre-tax) prices, and the equilibrium response which plays out as prices change. Our main result demonstrates that under weak regularity conditions, regardless of the details of behavioural preferences, mistakes and constraints on decision-making, the long-run equilibrium will involve a greater capital-labour ratio if and only if the direct response (from the corresponding consumption-saving model) involves an increase in aggregate savings. One implication of this result is that, from a qualitative point of view, behavioural biases matter for long-run equilibrium if and only if they change the direction of the direct response. We provide detailed illustrations of how this result can be applied and generate new insights using models of misperceptions, self-control and temptation, and naive and sophisticated quasi-hyperbolic discounting.

Emerging markets have experienced large human and economic costs from coronavirus disease 2019, and their tight fiscal space has limited the support extended to their citizens. We study the impact of an epidemic on economic and health outcomes by integrating epidemiological dynamics into a sovereign default model. The sovereign’s option to default tightens fiscal space and results in an epidemic with limited mitigation and depressed consumption. A quantitative analysis of our model accounts well for the dynamics of fatalities, social distancing, consumption, sovereign debt, and spreads in Latin America. We find that because of default risk, the welfare cost of the pandemic is about a third higher than it is in a version of the model with perfect financial markets. We study debt relief programs and find a compelling case for their implementation. These programs deliver large social gains, improving health and economic outcomes for the country at no cost to international lenders or financial institutions.