Truthful germs are contagious: A local-to-global characterization of truthfulness

We study the question of which social choice functions from an abstract type space to a set of outcomes are truthful, i.e., implementable by truthful mechanisms, when utilities are quasi-linear. For convex domains, our main theorem characterizes truthful social choice functions as those satisfying two properties: local weak monotonicity and vortex-freeness. The first of these constrains the function values at any two sufficiently proximal points, while the second asserts that its line integrals around sufficiently small triangular loops must vanish.The characterization implies a local-to-global principle that allows one to deduce truthfulness of a function from its behavior on arbitrarily small neighborhoods of each point. Other consequences include a simple alternate derivation of the Saks–Yu Theorem that weak monotonicity characterizes truthfulness of functions having a convex domain and finite range, and a sufficient condition for constructing truthful functions by “stitching together” truthful subfunctions on different subsets of the domain.     

Wealth effects and agency costs

We analyze how the agent's initial wealth affects the principal's expected profits in the standard principal–agent model with moral hazard.We show that if the principal prefers a poorer agent for all specifications of action sets, probability distributions, and disutility of effort, then the agent's utility of income must exhibit a coefficient of absolute prudence less than three times the coefficient of absolute risk aversion for all levels of income, thus strengthening the sufficiency result of Thiele and Wambach (1999). Also, we prove that there is no condition on the agent's utility of income alone that will make the principal prefer richer agents. Moreover, we show that, for an interesting class of problems, the principal prefers a relatively poorer agent if agent's wealth is sufficiently large. Finally, we discuss how alternative ways of modeling the agent's outside option affects the principal's preferences for agent's wealth.     

Premium auctions and risk preferences: An experimental study

In premium auctions, the highest losing bidder receives a reward from the seller. This paper studies the private value English premium auction (EPA) for different risk attitudes of bidders. We explicitly derive the symmetric equilibrium for bidders with CARA utilities and conduct an experimental study to test the theoretical predictions. In our experiment, subjects are sorted into risk-averse and risk-loving groups. We find that revenues in the EPA are significantly higher when bidders are risk loving rather than risk averse. These results are partly consistent with theory and confirm the general view that bidders' risk preferences constitute an important factor that affects bidding behavior and consequently also the seller's expected revenue. However, individual subjects rarely follow the equilibrium strategy and revenue in our experiment is lower than in the symmetric equilibrium.     

Endogenous human capital formation,distance to frontier and growth

We examine human capital's contribution to economy-wide technological progress through two channels – imitation and innovation – innovation being more skill-intensive than imitation. We develop a growth model based on the endogenous ability-driven skill acquisition decision of an individual. It is shown that skilled human capital is growth enhancing in the “imitation-innovation” regime and in the “innovation-only” regime whereas unskilled human capital is growth enhancing in the “imitation-only” regime. Steady state exists and, in the long run, the economy converges to the world technology frontier. In the diversified regime, technological progress raises the return to ability and generates an increase in wage inequality between and within groups – consistent with the pattern observed across countries.     

Are high–frequency traders informed?

Are high–frequency traders (HFTs) informed? To address this question, we examine HFTs' activity in the call auction environment, where speed-related trading is limited and signal processing capacity becomes more relevant. To model the call market, we consider the Kyle (1989) rational expectations framework for strategic trading. The test we propose for detecting informed HFTs in this market assesses potential deviations of the informativeness of HFTs' aggregate (net) demand, from the informativeness of the aggregate demand submitted by the rest of the traders. Data from the Euronext Paris preopening phase indicate that informed HFTs are present in the market just before the opening. Our results provide useful guidance for the assessment of the influence of HFTs’ quotes on price quality, an important issue for market regulators and policy makers.     

International Housing Markets and the U.S. Subprime Crisis

We propose a novel decomposition approach to study the degree of co-movement of international housing markets while distinguishing among different economic drivers. We find that the housing market variability for an average country was mainly driven by the common housing risk premium components during the years leading up to the 2007–08 subprime financial crisis. A decrease in the common housing risk premium was followed by a housing boom and economic expansion in the United States prior to the crisis. Our findings add to the understanding of the role of common risk factors across international housing markets before the crisis.     

Investor sentiment and the risk–return relation: A two-in-one approach

Traditional finance theory posits a positive risk–return relation, but empirical evidence is inconclusive. Retail investor sentiment has long been viewed as a distorting factor, while more recently institutional investor sentiment is thought to play a role. We examine the separate and joint impacts of retail and institutional investor sentiments on the risk-return relation. We find, at both market and firm levels, the risk-return relation is more likely to be distorted by the two investor-type sentiments jointly, rather than separately. We further find a cross-sectional pattern, with the risk-return relation being more sensitive to investor sentiment for stocks with specific characteristics.     

Prices and factor demand in an endogenized input–output model

This paper combines factor demand functions (for intermediate input and labour) and price equations (derived from a Generalized Leontief cost function) with the traditional input–output price model. The cost functions determine factor demands for materials and labour as well as output prices at given input prices. At the second level of aggregation, the intermediate demand as a single input is split proportional to the elements in the column of the technical coefficients matrix. The emphasis in this endogenization of technical coefficients is on two features. First, the repercussion of output on input prices, and, second, the link between the econometric model for the supply side and the input–output demand model.     

TRADE INTEGRATION,OUTSOURCING AND EMPLOYMENT IN AUSTRIA: A DECOMPOSITION APPROACH

Outsourcing and trade integration of advanced countries is debated with respect to employment effects, in particular for low educated workers – at least in relative terms. We study the employment effects – differentiated by educational attainment levels – of changes in the patterns of trade integration and outsourcing in the Austrian economy over the periods 1995–2000 and 2000–2005 using hierarchical decomposition analysis based on deflated input–output tables. Outsourcing is modeled as changes in the shares of domestically produced intermediates in total intermediates. A similar decomposition of the final demand vector allows us to draw conclusions on the overall employment effects of trade integration. The results suggest that the expected negative employment effects of outsourcing and rising import penetration have been overcompensated by increasing exports. Thus, the overall employment effects of Austrian trade integration have been positive for all educational attainment groups. However, whereas the total effects have been strongest for medium and high educated workers over the period 1995–2000, employment of low educated workers have been strongest and positively affected over the period 2000–2005. This pattern can be explained by a more sluggish export performance together with stronger negative effects of outsourcing and import penetration in medium and high-skill intensive products.     

Dynamic contracting under imperfect public information and asymmetric beliefs

We develop a dynamic principal–agent model to show how imperfect public information and asymmetric beliefs about payoff-relevant parameters, agency conflicts, and the agent's implicit incentives to influence the principal's posterior beliefs through his unobservable actions interact to affect optimal dynamic contracts. We make a methodological contribution to the literature by solving the continuous-time contracting problem using a discrete-time approximation approach. We obtain a simple characterization of optimal renegotiation-proof contracts in terms of the solution to a nonlinear ordinary differential equation (ODE). We then exploit the properties of the ODE to derive a number of novel implications for the dynamics of long-term contracts that alter the intuition gleaned from the previous literature. Optimism has a first-order impact on incentives, investment and output that could reconcile the “private equity” puzzle. Consistent with empirical evidence, the interaction between asymmetric beliefs, risk-sharing and adverse selection costs could cause the time-paths of the agent's incentive intensities to be increasing or decreasing. Our results also suggest that the incorporation of imperfect public information and asymmetric beliefs could potentially reconcile empirical evidence of an ambiguous relation between risk and incentives, and a non-monotonic relation between firm value and incentives. Permanent and transitory components of risk have differing effects on incentives, which suggest that empirical investigations of the link between risk and incentives should appropriately account for different components of risk.