Knowledge that Transforms

Abstract This article studies the relationship between patience and comparative development through a combination of reduced-form analyses and model estimations. Based on a globally representative dataset on time preference in 76 countries, we document two sets of stylized facts. First, patience is strongly correlated with per capita income and the accumulation of physical capital, human capital, and productivity. These correlations hold across countries, sub-national regions, and individuals. Second, the magnitude of the patience elasticity strongly increases in the level of aggregation. To provide an interpretive lens for these patterns, we analyse an overlapping generations model in which savings and education decisions are endogenous to patience, aggregate production is characterized by capital-skill complementarities, and productivity implicitly depends on patience through a human capital externality. In our model estimations, general equilibrium effects alone account for a non-trivial share of the observed amplification effects, and an extension to human capital externalities can quantitatively match the empirical evidence.

Abstract Empirical evidence on distributional preferences shows that people do not judge inequality as problematic per se but that they take into account the fairness or unfairness of the outcome. This article conceptualizes a view of unfair inequality and introduces a new measure of inequality based on two widely held fairness principles: equality of opportunity and freedom from poverty. It develops a method for decomposing inequality and its trends into an unfair and a fair component. We provide two empirical applications of our measure. First, we analyse the development of inequality in the US from 1969 to 2014 from a fairness perspective. Second, we conduct a corresponding international comparison between the US and 31 European countries in 2010. Our results document that unfair inequality matches the well-documented inequality growth in the US since 1980. This trend is driven by decreases in social mobility, i.e., increasing importance of parental education and occupation for the income of their children. Among the 32 countries of our international comparison, the land of opportunity ranks among the most unfair societies in 2010.

Abstract We study the severity of liquidity constraints in the U.S. housing market using a life-cycle model with uninsurable idiosyncratic risks in which houses are illiquid, but agents can extract home equity by refinancing their mortgages. The model implies that four-fifths of homeowners are liquidity constrained and willing to pay an average of 13 cents to extract an additional dollar of liquidity from their home. Most homeowners value liquidity for precautionary reasons, anticipating the possibility of income declines and the need to make mortgage payments. The model reproduces well the observed response of consumption to tax rebates and mortgage relief programs and predicts large welfare gains from policies aimed at providing temporary liquidity relief to homeowners.

Abstract How does the shadow banking system respond to changes in capital regulation of commercial banks? We propose a quantitative general equilibrium model with regulated and unregulated banks to study the unintended consequences of regulation. Tighter capital requirements for regulated banks cause higher convenience yield on debt of all banks, leading to higher shadow bank leverage and a larger shadow banking sector. At the same time, tighter regulation eliminates the subsidies to commercial banks from deposit insurance, reducing the competitive pressures on shadow banks to take risks. The net effect is a safer financial system with more shadow banking. Calibrating the model to data on financial institutions in the US, the optimal capital requirement is around 16%.

Abstract Using a quantitative model that features technical progress in automation and endogenous skill choice, we show that, given the current U.S. tax system, a sustained fall in automation costs can lead to a massive rise in income inequality. We characterize the optimal tax system in this model. We find that it is optimal to tax robots while the current generations of routine workers, who can no longer move to non-routine occupations, are active in the labour force. Once these workers retire, optimal robot taxes are zero.

Abstract This article analyses the dynamic spatial equilibrium of taxicabs and shows how common taxi regulations lead to substantial inefficiencies as a result of search frictions and mis-allocation. To analyse the role of regulation on frictions and efficiency, I pose a dynamic model of spatial search and matching between taxis and passengers. Using a comprehensive dataset of New York City yellow medallion taxis, I use this model to compute the equilibrium spatial distribution of vacant taxis and estimate intraday demand given price and medallion regulations. My estimates show that the weekday New York market achieves about $$$5.7 million in daily welfare or about $$$27 per trip, but an additional 53 thousand customers fail to find cabs due to search frictions. Counterfactual analysis shows that implementing simple tariff pricing changes can enhance allocative efficiency and expand the market, offering daily consumer surplus gains of up to $$$227 thousand and up to 49 thousand additional daily taxi-passenger matches, a similar magnitude to the gain in matches generated by adopting a perfect static matching technology.

Abstract The problem of demand inversion—a crucial step in the estimation of random utility discrete-choice models—is equivalent to the determination of stable outcomes in two-sided matching models. This equivalence applies to random utility models that are not necessarily additive, smooth, nor even invertible. Based on this equivalence, algorithms for the determination of stable matchings provide effective computational methods for estimating these models. For non-invertible models, the identified set of utility vectors is a lattice, and the matching algorithms recover sharp upper and lower bounds on the utilities. Our matching approach facilitates estimation of models that were previously difficult to estimate, such as the pure characteristics model. An empirical application to voting data from the 1999 European Parliament elections illustrates the good performance of our matching-based demand inversion algorithms in practice.

Abstract In 2008, Volkswagen introduced a new generation of “Clean Diesel” cars and heavily marketed them to environmentally conscious US consumers. Unknown to the public, these cars were anything but clean, emitting pollutants up to 150 times the level of comparable gas-fuelled cars. We study the rollout of these emissions-cheating diesel cars across the United States from 2008 to 2015 as a natural experiment to examine the impact of moderate levels of car pollution on infant and child health in the general population. Using the universe of vehicle registrations, we find that an additional cheating diesel car per 1,000 cars increases \mathrmPM_2.5, \mathrmPM_10, and ozone by 2, 2.2, and 1.3%, respectively, while the low birth weight rate and infant mortality rate increase by 1.9 and 1.7%, respectively. Similar impacts are found for acute asthma attacks in children. These health impacts occur at all pollution levels and across the socioeconomic spectrum.

Abstract Facing the same labour demand shock through imports from China, we show that men and women make different labour market and family adjustments that result in significant long-run gender inequality. The gender gap is driven by the female biological clock. Using population registers and matched employer-employee data from Denmark, we document that especially women in their late 30s, towards the end of their biological clock, decide to have a baby as the shock causes displacement. High-earning women in leadership positions and women who need to acquire new human capital are central because their new employment would require particularly high investments that are incompatible with having a newborn in the short time remaining on the biological clock. While children penalize women in the labour market, we show that due to the biological clock an otherwise gender-neutral shock leads to a gender gap in the labour market.

Abstract This article generalizes central results from the theory of (endogenously) directed technical change to settings where technology does not take a labour-augmenting form and with arbitrarily many levels of skill. Building on simple notions of complementarity, the results remain intuitive despite their generality. The developed theory allows to study the endogenous determination of labour-replacing, that is, automation technology through the lens of directed technical change theory. In an assignment model with a continuum of differentially skilled workers and capital, where capital perfectly substitutes for labour in the production of tasks, any increase in the relative supply of skilled workers stimulates investment into improving the productivity of capital, potentially leading skill premia to increase in relative skill supply. Relatedly, trade with a skill-scarce country discourages improvements in capital productivity, potentially reversing the standard Heckscher–Ohlin effects.