Knowledge that Transforms

We examine the role of individual discount rates in energy efficiency decisions using evidence from an extensive survey of US homeowners to elicit preferences for energy efficiency and cash flows over time. We find considerable heterogeneity in individual discount rates. We also find that individual time preferences systematically influence willingness to invest in energy efficiency, as measured through product choices, required payback periods, and energy efficiency tax credit claims. Education is a key driver of individual discount rates. Our findings highlight the importance of individual discount rates to understanding energy efficiency investments, the energy-efficiency gap, and policy evaluation.

Does the “soft side” of management matter? Many managers assert that “firm culture” is strongly correlated with productivity, but there are few robust tests of this assertion. In a set of field experiments, we study driver productivity within a large US logistics company that is arguably transitioning from one relational contract to another, while leaving formal practices and incentives unchanged. We find that sites under the new contract are associated with 1/8 percent higher productivity. Our findings suggest that relational contracts have a first-order effect on productivity and that they can be altered over time.

This paper examines the relationship between income, pollution, and mortality in China from 1991-2012. Using first-difference models, we document a robust positive association between city-level GDP and life expectancy. We also find a negative association between city-level particulate air pollution exposure and life expectancy that is driven by elevated cardiorespiratory mortality rates. The results suggest that while China's unprecedented economic growth over the last two decades is associated with health improvements, pollution has served as a countervailing force.

In the United States in the late 19th and early 20th century, large cities had extremely high death rates from infectious disease. Within major cities such as New York City and Philadelphia, there was significant variation at any point in time in the mortality rate across neighborhoods. Between 1900 and 1930 neighborhood mortality convergence took place in New York City and Philadelphia. We document these trends and discuss their consequences for neighborhood quality of life dynamics and the economic incidence of who gains from effective public health interventions.

Most empirical policy work focuses on causal inference. We argue an important class of policy problems does not require causal inference but instead requires predictive inference. Solving these “prediction policy problems” requires more than simple regression techniques, since these are tuned to generating unbiased estimates of coefficients rather than minimizing prediction error. We argue that new developments in the field of “machine learning” are particularly useful for addressing these prediction problems. We use an example from health policy to illustrate the large potential social welfare gains from improved prediction.

We examine the relationship between capitalism and income inequality for a large sample of countries using an adjusted economic freedom index as proxy for capitalism. Our results suggest that there is no robust relationship between economic freedom and Gini coefficients based on gross income. Subsequently, we analyze the relationship between income redistribution and ethno-linguistic fractionalization. We find that the impact of ethno-linguistic fractionalization on income redistribution is conditional on the level of economic freedom: countries that have a high degree of fractionalization redistribute income less, while capitalist countries that have a low degree of fractionalization redistribute income more.

We survey and apply several techniques from the statistical and computer science literature to the problem of demand estimation. To improve out-of-sample prediction accuracy, we propose a method of combining the underlying models via linear regression. Our method is robust to a large number of regressors; scales easily to very large data sets; combines model selection and estimation; and can flexibly approximate arbitrary non-linear functions. We illustrate our method using a standard scanner panel data set and find that our estimates are considerably more accurate in out-of-sample predictions of demand than some commonly used alternatives.

I study an economy where asymmetric information about the quality of capital endogenously determines liquidity. Liquid funds are key to relaxing financial constraints on investment and employment. These funds are obtained by selling capital or using it as collateral. Liquidity is determined by balancing the costs of obtaining liquidity under asymmetric information against the benefits of relaxing financial constraints. Aggregate fluctuations follow increases in the dispersion of capital quality, which raise the cost of obtaining liquidity. An estimated version of the model can generate patterns for quantities and credit conditions similar to the Great Recession. (JEL D82, E22, E24, E32, E44, G01)

Following FCC pressure to end bill shock, cellular carriers now alert customers when they exceed usage allowances. We estimate a model of plan choice, usage, and learning using a 2002–2004 panel of cellular bills. Accounting for firm price adjustment, we predict that implementing alerts in 2002–2004 would have lowered average annual consumer welfare by $33. We show that consumers are inattentive to past usage, meaning that bill-shock alerts are informative. Additionally, our estimates imply that consumers are overconfident, underestimating the variance of future calling. Overconfidence costs consumers $76 annually at 2002–2004 prices. Absent overconfidence, alerts would have little to no effect. (JEL D12, D18, L11, L96, L98)

In Capital in the Twenty-First Century, Thomas Piketty uses the market value of tradable assets to measure both productive capital and wealth. As a measure of wealth this is problematic because it ignores the value of human capital and transfer wealth, which have grown enormously over the last 300 years. Thus the constancy of the wealth/income ratio as portrayed in his data is an illusion. Further, the types of wealth that he does not measure are more equally distributed than tradable assets. The approach also incorrectly identifies capital gains due to reduced discount rates as increases in the capital stock.