Knowledge that Transforms

Local air pollution has led authorities in many cities around the world to impose limits on car use by means of driving restrictions or license-plate bans. By placing uniform restrictions on all cars, many of these programs have created incentives for drivers to buy additional, more polluting cars. We study vintage-specific restrictions, which place heavy limits on older, polluting vehicles and no limits on newer, cleaner ones. We use a novel model of the car market and results from Santiago’s 1992 program, the earliest program to use vintage-specific restrictions, to show that such restrictions should be designed to work exclusively through the extensive margin (type of car driven), never through the intensive margin (number of miles driven). If so, vintage restrictions can yield important welfare gains by moving the fleet composition toward cleaner cars, comparing well to alternative instruments such as scrappage subsidies and pollution-based registration fees.

We document the transmission of large-scale asset purchases by the Federal Reserve to the real economy using rich borrower-linked mortgage-market data and an identification strategy based on mortgage market segmentation. We find that central bank QE1 MBS purchases substantially increased refinancing activity, reduced interest payments for refinancing households, led to a boom in equity extraction, and increased aggregate consumption. Relative to QE-ineligible jumbo mortgages, QE-eligible conforming mortgage interest rates fell by an additional 40 bp and refinancing volumes increased by an additional 56% during QE1. We estimate that households refinancing during QE1 increased their durable consumption by 12%. Our results highlight that the transmission of unconventional monetary policy to the real economy depends crucially on the composition of assets purchased and the degree of segmentation in the market.

This article identifies an equilibrium theory of wage formation and endogenous quit turnover in a labour market with on-the-job search, where risk averse workers accumulate human capital through learning-by-doing and lose skills while unemployed. Optimal contracting implies the wage paid increases with experience and tenure. Indirect inference using German data determines the deep parameters of the model. The estimated model not only reproduces the large and persistent fall in wages and earnings following job loss, a new structural decomposition finds foregone human capital accumulation (while unemployed) is the worker’s major cost of job loss.

I propose a novel general equilibrium framework to quantify the impact of law enforcement on the internal organization of firms and thereby on aggregate outcomes. The model features an agency problem between the firm and its middle managers. Imperfect law enforcement allows middle managers to divert revenue from firms, which reduces delegation and constrains firm size. I use French matched employer–employee data for evidence of the model’s pattern of managerial wages. Relative to the French benchmark economy, reducing law enforcement to its minimum value decreases GDP (equivalently, total factor productivity; TFP) by 23% and triples the self-employment rate. Consistent with the model, I document cross-country empirical evidence of a positive correlation between law enforcement indicators and the aggregate share of managerial workers. Mapped across the world, the model explains 3–6% of the ratio in GDP per worker between the poorest and richest quintile of countries, and 6–11% of their TFP ratio.

We study how the diffusion of being pivotal affects immoral outcomes. In our main experiment, subjects decide about agreeing to kill mice and receiving money versus objecting to the killing and foregoing the monetary amount. In a baseline condition, subjects decide individually about the life of one mouse. In the main treatment, subjects are organized into groups of eight and decide simultaneously. Eight mice are killed if at least one subject opts for killing. The fraction of subjects agreeing to kill is significantly higher in the main condition compared with the baseline condition. In a second experiment, we run the same baseline and main conditions but use a charity context and additionally study sequential decision-making. We replicate our finding from the mouse paradigm. We further show that the observed effects increase with experience, i.e., when we repeat the experiment for a second time. For both experiments, we elicit beliefs about being pivotal, which we validate in a treatment with non-involved observers. We show that beliefs are a main driver of our results.

This article incorporates banks and banking panics within a conventional macroeconomic framework to analyse the dynamics of a financial crisis of the kind recently experienced. We are particularly interested in characterizing the sudden and discrete nature of banking panics as well as the circumstances that make an economy vulnerable to such panics in some instances but not in others. Having a conventional macroeconomic model allows us to study the channels by which the crisis affects real activity both qualitatively and quantitatively. In addition to modelling the financial collapse, we also introduce a belief driven credit boom that increases the susceptibility of the economy to a disruptive banking panic.

An increasing number of police departments use information technology (IT) to optimize patrolling strategies, yet little is known about its effectiveness in preventing crime. Based on quasi-random access to “predictive policing,” this study shows that IT improves police productivity as measured by crime clearance rates. Thanks to detailed information on individual incidents and offender-level identifiers it also shows that criminals strategies are predictable. Moreover, the introduction of predictive policing coincides with a large negative trend-discontinuity in crime rates. The benefit–cost ratio of this IT innovation appears to be large.

How should macroprudential policy be designed when policymakers also have access to liquidity provision tools to manage crises? We show in a tractable model of systemic banking risk that there are three factors at play: first, ex post liquidity provision mitigates financial crises, and this reduces the need for macroprudential policy. In the extreme, if liquidity provision is untargeted and costless or if it completely forestalls crises by credible out-of-equilibrium lending-of-last-resort, there is no role left for macroprudential regulation. Second, however, macroprudential policy needs to consider the ex ante incentive effects of targeted liquidity provision. Third, if shadow banking reduces the effectiveness of macroprudential instruments, it is optimal to commit to less generous liquidity provision as a second-best substitute for macroprudential policy.

This article studies a security design problem featuring flexible information acquisition. To raise liquidity, a seller issues a security backed by her asset in place at the price she proposes to a buyer. Before deciding whether to accept the offer, the buyer can acquire costly information about the underlying asset. This case differs from the existing literature on security design, in that the buyer has the full flexibility of choosing not only the amount of resources to spend in information acquisition, but also how to allocate them, depending on the shape of the security. Debt is shown to be the unique optimal security for the seller, as its payoff is the least sensitive to the value of its underlying asset. This minimizes the buyer’s incentive to acquire information and mitigates the resulting adverse selection. I do not assume monotonicity of the feasible securities nor impose various distributional assumptions on information structures. Instead, I identify conditions for general information costs that support the results.

Using detailed panel data from the Pale of Settlement area between 1800 and 1927, we document that anti-Jewish pogroms—mob violence against the Jewish minority—broke out when economic shocks coincided with political turmoil. When this happened, pogroms primarily occurred in places where Jews dominated middleman occupations, i.e., moneylending and grain trading. This evidence is inconsistent with the scapegoating hypothesis, according to which Jews were blamed for all misfortunes of the majority. Instead, the evidence is consistent with the politico-economic mechanism, in which Jewish middlemen served as providers of insurance against economic shocks to peasants and urban grain buyers in a relationship based on repeated interactions. When economic shocks occurred in times of political stability, rolling over or forgiving debts was an equilibrium outcome because both sides valued their future relationship. In contrast, during political turmoil, debtors could not commit to paying in the future, and consequently, moneylenders and grain traders had to demand immediate (re)payment. This led to ethnic violence, in which the break in the relationship between the majority and Jewish middlemen was the igniting factor.