Knowledge that Transforms

We provide a general theoretical characterization of how firms' technology choice on a technology frontier determines the long-run elasticity of substitution between capital and labour. We show that the shape of the frontier determines factor shares and the elasticity of substitution between capital and labour. If there are adjustment costs to technology choice, the short-and long-run elasticities differ, with the long-run always higher. If the technology frontier is log-linear, the production function becomes Cobb-Douglas in the long run but, consistent with empirical evidence, short-run dynamics are characterized by gross complementarity. The approach is easily implementable and yields a powerful way to introduce CES-type production functions in macroeconomic models. We provide an illustration within an estimated dynamic general equilibrium model and show that the use of our production technology provides a good match for the short-and medium-run behaviour of the U.S. labour share.

We study platform markets in which the information about users’ preferences is dispersed. First, we show how the dispersion of information introduces idiosyncratic uncertainty about participation decisions and how the latter shapes the elasticity of the demands and the equilibrium prices. We then study the effects on profits, consumer surplus, and welfare of platform design, blogs, forums, conferences, advertising campaigns, post-launch disclosures, and other information management policies affecting the agents’ ability to predict participation decisions on the other side of the market.

Standard optimal Debt Management (DM) models prescribe a dominant role for long bonds and advocate against issuing short bonds. They require very large positions in order to complete markets and assume each period that governments repurchase all outstanding bonds and reissue (r/r) new ones. These features of DM are inconsistent with U.S. data. We introduce incomplete markets via small transaction costs which serves to make optimal DM more closely resemble the data : r/r are negligible, short bond issuance substantial and persistent and short and long bonds positively co-vary. Intuitively, long bonds help smooth taxes over states and short bonds over time. Solving incomplete market models with multiple assets is challenging so a further contribution of this article is introducing a novel computational method to find global solutions.

What are the origins and consequences of the state as a provider of public goods? We study public goods provision established through new laws in German cities during the 1500s. Cities that adopted the laws subsequently began to differentially produce and attract human capital and to grow faster. Legal change occurred where ideological competition introduced by the Protestant Reformation interacted with local politics. We study plagues that shifted local politics in a narrow period as sources of exogenous variation in public goods institutions, and find support for a causal interpretation of the relationship between legal change, human capital, and growth.

Non-equilibrium models of choice (e.g. level-k reasoning) have significantly different, sometimes more accurate, predictions in games than does Nash equilibrium. When it comes to the maximal set of functions that are implementable in mechanism design, however, they turn out to have similar implications. Focusing on single-valued rules, we discuss the role and implications of different behavioural anchors (arbitrary level-0 play), and prove a level-k revelation principle. If a function is level-k implementable given any level-0 play, it must obey a slight weakening of standard strict incentive constraints. Further, the same condition is also sufficient for level-k implementability, although the role of specific level-0 anchors is more controversial for the sufficiency argument. Nonetheless, our results provide tight characterizations of level-k implementable functions under a variety of level-0 play, including truthful, uniform, and atomless anchors.

We empirically study the effects of broadband internet diffusion on local election outcomes and on local government policies using rich data from the U.K. Our analysis shows that the internet has displaced other media with greater news content (i.e. radio and newspapers), thereby decreasing voter turnout, most notably among less-educated and younger individuals. In turn, we find suggestive evidence that local government expenditures and taxes are lower in areas with greater broadband diffusion, particularly expenditures targeted at less-educated voters. Our findings are consistent with the idea that voters’ information plays a key role in determining electoral participation, government policies, and government size.

We build a dynamic model of migration where, in addition to standard relocation costs, workers face spatial frictions that decrease their ability to compete for distant job opportunities. We estimate the model on a matched employer–employee panel dataset describing labour market transitions within and between the 100 largest French cities. Our identification strategy is based on the premise that frictions affect the frequency of job transitions, while mobility costs impact the distribution of accepted wages. We find that: (1) controlling for spatial frictions reduces mobility cost estimates by one order of magnitude; (2) the urban wage premium is driven by better opportunities for local job-to-job transitions in larger cities; (3) migration reduces lifetime inequalities by providing insurance against unsatisfactory initial location draws; (4) labour mobility policies based on relocation subsidies are inefficient, unlike switching from nationwide to local minimum wages.

Large multi-product firms dominate international trade flows. Using novel linked production and export data at the firm-product level, we find that the overwhelming majority of manufacturing firms export products that they do not produce. Three quarters of the exported products and 30% of export value from Belgian manufacturers are in goods that are not produced by the firm, so-called Carry-Along Trade (CAT). The number of CAT products is strongly increasing in firm productivity while the number of produced products that are exported is weakly increasing in firm productivity. We propose a general model of production and sourcing at multi-product firms and explore new demand- and supply-side modelling features capable of generating predictions consistent with the empirical findings. Export price data and company interviews offer suggestive evidence for the presence of demand-scope complementarities.

We develop and evaluate experimentally a novel tool that redesigns the job search process by providing tailored advice at low cost. We invited jobseekers to our computer facilities for twelve consecutive weekly sessions to search for real jobs on our web interface. For one-half, instead of relying on their own search criteria, we use readily available labour market data to display relevant alternative occupations and associated jobs. The data indicate that this broadens the set of jobs they consider and increases their job interviews especially for participants who otherwise search narrowly and have been unemployed for a few months.

Using a novel source of quasi-experimental variation in interest rates, we develop a new approach to estimating the Elasticity of Intertemporal Substitution (EIS). In the U.K., the mortgage interest rate features discrete jumps—notches—at thresholds for the loan-to-value (LTV) ratio. These notches generate large bunching below the critical LTV thresholds and missing mass above them. We develop a dynamic model that links these empirical moments to the underlying structural EIS. The average EIS is small, around 0.1, and quite homogeneous in the population. This finding is robust to structural assumptions and can allow for uncertainty, a wide range of risk preferences, portfolio reallocation, liquidity constraints, present bias, and optimization frictions. Our findings have implications for the numerous calibration studies that rely on larger values of the EIS.