Knowledge that Transforms

We derive wage equations with individual-specific coefficients from a structural model of human capital investment over the life-cycle. This model allows for interruptions in labour market participation and deals with missing data and attrition problems. We propose a new framework that deals with missingness at random and is based on factor decompositions that allow for flexible control of selection. Our approach leads to an interactive effect wage specification, which we estimate using long administrative panel data on male wages in the private sector in France. A structural function approach shows that interruptions negatively affect average wages. Interestingly, they also negatively affect the inter-decile range of wages after twenty years. This is only partly due to the fact that interruptions are endogenous.

In many industries, buyers diversify their supplier base to manage supplier disruption risk. We investigate the importance of such diversification as a determinant of demand and supplier entry in the context of the internet backbone, the worldwide network of undersea fibre-optic cables that underpins the internet. We specify a model of international bandwidth demand and cable operators’ dynamic entry and supply choices. The model is estimated using novel data on cross-border data flows, prices, cable characteristics, and disruptions. Counterfactual analysis reveals that supplier diversification accounts for a large share of entry and surplus created between 2005 and 2021. Relative to the socially optimal level of entry, distortions due to suppliers’ inability to capture fully the social benefits of diversity are as large as distortions due to business stealing.

We analyse the equilibrium effects of “bid shopping”—a contractor soliciting a subcontractor bid for part of a project prior to a procurement auction, then showing that bid to a competing subcontractor in an attempt to secure a lower price. Such conduct is widely criticized as unethical by professional organizations and has been the target of legislation at both the federal and state level but is widespread in procurement auctions in many places. We find that in equilibrium, a winning contractor’s practice of shopping her subcontractor’s bid to other subcontractors who have already submitted bids is welfare-decreasing, while shopping bids to new subcontractors who have not yet bid can be welfare-increasing, particularly when subcontractors’ bid preparation costs are sufficiently high.

We provide a finite sample inference method for the structural parameters of Manski's semiparametric binary response model under a conditional median restriction. This is achieved by exploiting distributional properties of observable outcomes conditional on the observed sequence of exogenous variables. Moment inequalities conditional on the size n sequence of exogenous covariates are constructed, and the proposed test statistic is a monotone function of violations of the corresponding sample moment inequalities. The critical value used for inference is provided by the appropriate quantile of a known function of n independent Bernoulli random variables and does not require the use of a cube root asymptotic approximation employing a point estimator of the target parameter. Simulation studies demonstrate favourable finite sample performance of the test in comparison to several existing approaches. Empirical use is illustrated with an application to the classical setting of transportation choice.

People’s value of their own time is a key input in public policy evaluations—these evaluations should account for time taken away from work or leisure as a result of policy. Measuring this value for the self-employed is challenging, as, by definition, it is not priced by the market. Using rich choice data collected from farming households in western Kenya, we show that households exhibit non-transitive preferences. As a result, neither market wages nor standard valuation techniques correctly measure participants’ value of time. Using a structural model, we identify the behavioural wedges in participants’ choices and find that distortions appear when households exchange cash either for time or for goods. Our model estimates suggest that valuing the time of the self-employed at 60% of the market wage is a reasonable rule of thumb.

When firms finance using long-term nominal debt issued by financial intermediaries, changes in expected inflation lead to a wealth transfer across sectors. Higher expected inflation decreases firms’ real liabilities and default risk, which helps reduce debt overhang. However, it hurts intermediaries’ real assets, leading to a contraction in credit supply. We theoretically demonstrate that intermediary financing conditions play a key role in the transmission of nominal shocks, influencing the premium investors require for bearing inflation risk. We provide empirical evidence supporting our novel inflation transmission mechanism and connect our findings to the banking stress of 2023. We also show that Taylor rules responding to both financial and real variables can help stabilise our economy.

We exploit a unique event to study the extent to which popular attitudes towards trade are driven by economic fundamentals. In 2007, Costa Rica put a free trade agreement (FTA) to a national referendum. With a single question on the ballot, 59% of Costa Rican adult citizens cast a vote on whether they wanted an FTA with the U.S. to be ratified or not. We merge disaggregated referendum results, which break new ground on anonymity-compatible voting data, with employer–employee, customs, and firm-to-firm transactions data, and data on household composition and expenditures. We document that a firm’s exposure to the FTA, directly and via input–output linkages, significantly influences the voting behaviour of its employees. This effect dominates that of sector-level exposure and is greater for voters aligned with pro-FTA political candidates. We also show that citizens considered the expected decrease in consumer prices when exercising their vote. Overall, economic factors explain 7% of the variation in voting patterns, which cannot be accounted for by non-economic factors such as political ideology, and played a pivotal role in this vote.

Many auctions and procurement contests entail non-trivial bidding costs, which makes the bidders’ participation decisions endogenous to the auction design. We analyse the effect of different auction rules on potential bidders’ incentives to participate. We focus on first-price auctions with affiliated common values and a large pool of potential bidders. Our main interest is on auctions where the realized number of bidders is unknown at the bidding stage. In contrast to the standard case, both participation and bidding decisions are often non-monotonic in the symmetric equilibrium of our model. The expected revenue to the seller is often higher in the auction where the realized number of participating bidders is not disclosed.

We study the effect of diminishing search frictions in markets with adverse selection by presenting a model in which agents with private information can simultaneously contact multiple trading partners. We highlight a new trade-off: facilitating contacts reduces coordination frictions but also the ability to screen agents’ types. We find that, when agents can contact sufficiently many trading partners, fully separating equilibria obtain only if adverse selection is sufficiently severe. When this condition fails, equilibria feature partial pooling and multiple equilibria co-exist. We show that facilitating contacts can lead to a reduction in welfare. In the limit, as the number of contacts becomes large, some of the equilibria converge to the competitive outcomes of Akerlof, including Pareto-dominated ones; other pooling equilibria continue to feature frictional trade in the limit, where entry is inefficiently high. Our findings provide a basis to assess the effects of recent technological innovations that have made meetings easier.

This paper estimates the consumer surplus from using alternative payment methods. We use evidence from Uber rides in Mexico, where riders have the option to use cash or cards to pay for rides. We design and conduct three large-scale field experiments, which involved approximately 400,000 riders. We also build a structural model which, disciplined by our new experimental data, allows us to estimate the loss of private benefits for riders when a ban on cash payments is implemented. We find that Uber riders who use cash as means of payment either sometimes or exclusively suffer an average loss of approximately 40–50% of their total trip expenditures paid in cash before the ban. The magnitude of these estimates reflects the intensity with which cash is used in the application, the shape of the demand curve for Uber rides, and the imperfect substitutability across means of payments. Welfare losses fall mostly on the least-advantaged households, who rely more heavily on the cash payment option.