Incomplete information and singleton cores in matching markets

We study ordinal Bayesian Nash equilibria of stable mechanisms in centralized matching markets under incomplete information. We show that truth-telling is an ordinal Bayesian Nash equilibrium of the revelation game induced by a common belief and a stable mechanism if and only if all the profiles in the support of the common belief have singleton cores. Our result matches the observations of Roth and Peranson [The redesign of the matching market for American physicians: some engineering aspects of economic design, Amer. Econ. Rev. 89 (1999) 748-780] in the National Resident Matching Program (NRMP) in the United States: (i) the cores of the profiles submitted to the clearinghouse are small and (ii) while truth-telling is not a dominant strategy most participants in the NRMP truthfully reveal their preferences.     

Imperfect competition in two-sided matching markets

This paper considers a simple equilibrium model of an imperfectly competitive two-sided matching market. Firms and workers may have heterogeneous preferences over matches on the other side, and the model allows for both uniform and personalized wages or contracts. To make the model tractable, I use the Azevedo and Leshno (2013) framework, in which a finite number of firms is matched to a continuum of workers.In equilibrium, even if wages are exogenous and fixed, firms have incentives to strategically reduce their capacity, to increase the quality of their worker pool. The intensity of incentives to reduce capacity is given by a simple formula, analogous to the classic Cournot model, but depends on different moments of the distribution of preferences. I compare markets with uniform and personalized wages. For fixed quantities, markets with personalized wages always yield higher efficiency than markets with uniform wages, but may be less efficient if firms reduce capacity to avoid bidding too much for star workers.     

Harmful signaling in matching markets

Several labor markets, including the job market for new Ph.D. economists, have recently developed formal signaling mechanisms. We show that such mechanisms are harmful for some environments. While signals transmit previously unavailable information, they also facilitate information asymmetry that leads to coordination failures. In particular, we consider a two-sided matching game of incomplete information between firms and workers. Each worker has either the same “typical” known preferences with probability close to one or “atypical” idiosyncratic preferences with the complementary probability close to zero. Firms have known preferences over workers. We show that under some technical condition if at least three firms are responsive to some workerʼs signal, the introduction of signaling strictly decreases the expected number of matches.     

Collateral constraints and rental markets

We study a benchmark model with collateral constraints and heterogeneous discounting. Contrarily to a rich literature on borrowing limits, we allow for rental markets. By incorporating this missing market, we show that impatient agents choose to rent rather than to own the collateral in the neighborhood of the deterministic steady state. Consequently, impatient agents are not indebted and borrowing constraints play no role in local dynamics.     

Informational efficiency: ranking markets

Summary. The paper studies informational properties of three types of imperfectly competitive markets: a one-signal speculative market (OSS market) in which agents have only private information about the fundamental value (v) of the risky asset traded, a two-signal speculative market (TSS market) in which agents have private information about both v and the asset supply, and a market in which agents are endowed with both information about v and shares of the risky asset traded. In this last market (JA market), agents have joint activities: they trade for both speculative and hedging purposes. It is shown that (i) the JA market and the OSS market are the most and the least efficient, respectively, and (ii) the levels of informational efficiency in the three markets are inversely correlated with the intensities with which traders use their private information about the fundamental value of the asset. Received May 28, 1999; revised version: May 28, 1999     

Matching and bargaining models of markets: approximating small markets by large markets

Summary. We show that the equilibrium of a matching and bargaining model of a market in which there is a finite number of agents at each date need not be near the equilibrium of a market with a continuum of agents, although matching probabilities are the same in both markets. Holding the matching process fixed, as the finite market becomes large its equilibrium approaches the equilibrium of its continuum limit.Received: January 22, 1996; revised version: September 24, 1996This revised version was published online in February 2005 with corrections to the cover date.     

Cointegration networks in stock markets

We use a novel approach based on a combination of network and cointegration analysis to examine linkages between stock markets across market cycles. Our results show that long-run linkages are likely to be global rather than regional and that market turbulence increases linkages. However, we find no widespread common stochastic trends between markets and neither are we able to draw a conclusion that major financial markets display influences network linkages.     

Matching markets with price bargaining

The extant microeconomic literature on matching markets assumes ordinal preferences for matches, while bargaining within matches is mostly excluded. Central for this paper, however, is bargaining over joint profits from potential matches. We investigate, both theoretically and experimentally, a seemingly simple allocation task in a 2×2 market with repeated negotiations. When inefficiency is possible, about 1/3 of the complete matches are inefficient and, overall, more than 3/4 of the experimental allocations are unstable. These results strongly contradict existing bargaining theories requiring efficient matches. Even with regard to efficient matches, the tested theories perform poorly. Standard bargaining and behavioral concepts, such as Selten’s (1972) Equal Division Core, are outperformed by the simplistic ε-Equal Split, i.e., an equal split of the joint profit plus/minus ε.     

Optimal location in two-sided markets

As the network externality in an industrial organization has been widely discussed in recent years, many researchers in the field have noted a particular type of market, the so-called two-sided market. In a two-sided market, two or more groups of agents such as buyers and sellers interact while exerting cross-group externalities upon each other. They interact with each other via some sort of medium, called the “platform” of interaction. This paper integrates the concept of two-sided markets into the optimal location problem for two platform providers. We show that when the two groups of customers' cross-side network externalities are equal, the duopoly platforms will agglomerate at the market center with no undercutting. However, disparate conditions exist under which the duopoly platforms will stay apart at the market endpoints, or agglomerate at either endpoint, with no undercutting.     

Game,set and match: the favourite-long shot bias in tennis betting exchanges

We test for the existence of Favourite-Longshot Bias (FLB) in tennis betting exchanges. Despite these being order-driven markets, with no direct participation from bookmakers, we have found very similar results to those obtained by Lahvi?ka (2014) for bookmakers’ betting markets: the bias is stronger in matches between lower-ranked players, in later round matches and in high profile tournaments. This suggests that bookmakers’ adjustments to respond to informed betting are not the main driver of FLB. The varying magnitude of the bias across different types of event in the main market also weakens arguments linking FLB to gamblers’ risk preferences, and suggests the need to consider the microstructure features of the market together with the cognitive biases highlighted in the behavioural finance literature.     

Optimal truncation in matching markets

Although no stable matching mechanism can induce truth-telling as a dominant strategy for all participants (Roth, 1982), recent studies have presented conditions under which truthful reporting by all agents is close to optimal (Immorlica and Mahdian, 2005, Kojima and Pathak, 2009, Lee, 2011). Our results demonstrate that in large, uniform markets using the Men-Proposing Deferred Acceptance Algorithm, each woman's best response to truthful behavior by all other agents is to truncate her list substantially. In fact, the optimal degree of truncation for such a woman goes to 100% of her list as the market size grows large. In general one-to-one markets we provide comparative statics for optimal truncation strategies: reduction in risk aversion and reduced correlation across preferences each lead agents to truncate more. So while several recent papers focused on the limits of strategic manipulation, our results serve as a reminder that without pre-conditions ensuring truthful reporting, there exists a potential for significant manipulation even in settings where agents have little information.     

Interest arbitrage in the Euro-currency markets

This study investigates how interest rates in the non-dollar Euro-currency markets are determined. Each of these Euro-currency rates is linked to the Euro-dollar rate through arbitrage operations undertaken by banks. Evidence from regressions of the Euro-currency rates on the Euro-dollar rate and the corresponding forward premium confirms that each non-dollar rate adheres closely to interest parity. Arbitrage results in unifying the Euro-currency markets so that supply and demand pressures in any individual market are spread throughout other Euro-currency markets. Because of the overwhelming size of the Euro-dollar market, conditions in this market tend to dominate conditions in the remaining Euro-currency markets.     

Inducing liquidity in thin financial markets through combined-value trading mechanisms

Asset pricing theory hypothesizes that investors are only interested in portfolios; individual securities are evaluated only in terms of their contribution to portfolio risk and return. Yet, standard financial market design is that of parallel, unconnected markets, whereby investors cannot submit orders in one market conditional on events in others. When markets are thin, this exposes them to substantial execution risk. Fear of ending up with unbalanced portfolios after trading may even keep investors from submitting orders, further eroding liquidity and the ability of markets to equilibrate. The suggested solution is a portfolio trading mechanism referred to as combined-value trading (CVT). Investors are allowed to submit orders for packages of securities and the system matches trades and computes prices by optimally combining portfolio orders in an open book. We study the performance of the CVT mechanism experimentally and compare it to the performance of parallel, unconnected double auctions in experiments with similar parametrization and either a similar number of subjects or substantially thicker markets. We present evidence that our portfolio trading mechanism facilitates equilibration to the extent that the thicker markets do. Inspection of order submission and trade activity reveals that subjects manage to exploit the direct linkages between markets enabled by the CVT system.     

Networks in labor markets: Wage and employment dynamics and inequality

We present a model of labor markets that accounts for the social network through which agents hear about jobs. We show that both wages and employment are positively associated (a strong form of correlation) across time and agents. We also analyze the decisions of agents regarding staying in the labor market or dropping out. If there are costs to staying in the labor market, then networks of agents that start with a worse wage status will have higher drop-out rates and there will be a persistent differences in wages between groups according to the starting states of their networks.     

Pricing and capacity provision in electricity markets: an experimental study

The creation of adequate investment incentives has been of great concern in the restructuring of the electricity sector. However, to achieve this, regulators have applied different market designs across countries and regions. In this paper we employ laboratory methods to explore the relationship between market design, capacity provision and pricing in electricity markets. Subjects act as firms, choosing their generation capacity and competing in uniform price auction markets. We compare three regulatory designs: (1) a baseline price cap system that restricts scarcity rents, (2) a price spike regime that effectively lifts these restrictions, and (3) a capacity market that directly rewards the provision of capacity. Restricting price spikes leads to underinvestment. In line with the regulatory intention both alternative designs lead to sufficient investment albeit at the cost of higher energy prices during peak periods and substantial capacity payments in the capacity market regime. To some extent these results confirm theoretical expectations. However, we also find lower than predicted spot market prices as sellers compete relatively intensely in capacities and prices, and the capacity markets are less competitive than predicted.     

Financial markets and the post-crisis scenario

Starting from August 2007, the FED intervened by injecting liquidity in the inter-banking market and reducing interest rates. Day after day, the financial markets register negative trends and rallies. This is not due to events which are particularly related to the market itself. This appeared in the days when there were government interventions, when everybody expected a positive sign in the financial market but a negative sign occurred. Sometimes, this is due to the intensity of actions taken by the governments. The markets always expect appropriate interventions (in terms of intensity). Looking at these market reactions (in unexpected signs) after each government action, we can suppose that policy makers underestimate the intensity of this crisis. The capacity of making enforcement on the system should avoid underlining the side of governance rules which will never be precise. Being able to count on an active control of the market dealers, broadly speaking is a way of giving active confidence to individual/institutional agents who decide the allocations of saving in the financial market. There is no such confidence at the moment, if one focuses only on the definitions of new rules. If one starts from existing rules and does continuous monitoring so that they are applied adequately at crucial moments, then one could reduce the possibility of facing new exceeding volatilities of banking securities in the stock market. This work is focused on understanding how governance as well as central banks’ policy impact on the crisis, as well as possible future scenarios.

Withholding investments in energy only markets: can contracts make a difference?

Although there are mechanisms to control market power in the spot market, withholding investments can still increase profits and hamper adequate capacity expansion. We examine the effect on investment of one suggested approach to reducing market power, contracting longer term. We construct a stylized model of an energy-only market where two firms, each specializing in one technology, invest in a first stage, contract part of their production in the second stage and sell the rest in the spot market in the third stage. We compare this model to one of an energy-only market having two stages, investment and a spot market. We find cases where the contracts change neither capacity nor peak prices, where the foreclosing effect of one player blocking the other from contracts markets increases investments and reduces prices, and where the opportunity to foreclose the market can incentivize one firm to lower its investment and increase its pricing power to the detriment of consumers. The model relies on the simplest possible assumptions of imperfect competition (subgame perfect equilibria with Cournot agents). We illustrate the different outcomes in a numerical example with two load steps (peak and off-peak) where we change one parameter, the height of the off-peak time segment. We find cases with increased and decreased capacity as well as no change in capacity. Since there is no general characterization of the consequences of contracts in this simple example, there can be no characterization in more complicated models that contain the market structures included here, and regulators or competition authorities cannot rely on contracts to induce sufficient capacity expansion by reducing market power. One other market mechanism that has been proposed to induce investment, a capacity auction with predetermined capacity requirements, is a potential alternative to limit market power that deserves further exploration to determine the extent to which it can provide an adequate incentive to invest in the presence of market power.     

Real estate markets and the macroeconomy: A dynamic coherence framework

This paper analyzes the dynamic interactions between real estate markets, in the US and the UK and their macroeconomic environments. We apply a new approach based on a dynamic coherence function (DCF) to study these interactions bringing together different real estate markets (the securitized market, the commercial market and the residential market). The results suggest that there is a common trend that drives the different real estate markets in the UK and the US, particularly in the long run, since they have a similar shape of the DCF. We also find that, in the US, wealth and housing expenditure channels are very conductive during real estate crises. However, in the UK, only the wealth effect is significant as a transmission channel during real estate market downturns. In addition, real estate markets in the UK and the US react differently to institutional shocks. This brings some insights on the conduct of monetary policy in order to avoid disturbances in real estate markets.     

Notes on marriage markets with weak externalities

We consider marriage markets with externalities. We focus on weak externalities, that is, markets in which each agent is primarily concerned about her partner. We formalize and prove the claim that weak externalities are not so significant in the marriage market: in this case, the ω-core and the α-core coincide and are both nonempty. In addition, we show that, if we allow agents to block matchings without changing their mate, the results do not longer hold.     

Emerging technologies in emerging markets: Introduction to the special section

Emerging technologies have significant implications and profound consequences for firms, markets, government policy, and society as a whole. In emerging markets, however, social uncertainties are as important as technological and market uncertainties, and moreover are somewhat more complex. The papers in this special section offer views of how these important social uncertainties can be considered concurrently with technological and market uncertainties, particularly because they play a relatively larger role in emerging markets than in more advanced markets.