Pairwise kidney exchange

The literature on exchange of indivisible goods finds natural application in the exchange of live donor kidneys for transplant. However, in kidney exchange, there are constraints on the size of exchanges. Initially, kidney exchanges are likely to be between just two patient-donor pairs. We show that, although this constraint eliminates some potential exchanges, there is a wide class of constrained-efficient mechanisms that are strategy-proof when patient-donor pairs and surgeons have 0-1 preferences. This includes deterministic mechanisms that accommodate the priority setting that organ banks currently use to allocate cadaver organs, and stochastic mechanisms that allow distributive justice issues to be addressed.     

The Implications for Econometric Modelling of Forecast Failure

To reconcile forecast failure with building congruent empirical models, we analyze the sources of mis-prediction. This reveals that ex ante forecast failure is purely a function of forecast-period events, not determinable from in-sample information. The primary causes are unmodelled shifts in deterministic factors, rather than model mis-specification, collinearity, or a lack of parsimony. We examine the effects of deterministic breaks on equilibrium-correction mechanisms, and consider the role of causal variables. Throughout, Monte Carlo simulation and empirical models illustrate the analysis, and support a progressive research strategy based on learning from past failures.     

Path-dependent economic progress and regress: The negative role of subsidies in economic growth

This paper develops a two-stage economic growth model with real options and examines the effects of various subsidy policies. The economic stages are the deterministic and stochastic AK stages, and the economy may shift between the two, depending upon state variables and technological shocks. This model allows for path-dependent economic growth that accounts for both club convergence and divergence across countries. Moreover, it is shown that under certain conditions, a decrease in the subsidy rate facilitates the shift from the deterministic to stochastic AK stages, which is defined as “economic progress”, even in the face of an economic crisis, while more subsidies delay economic progress and promote the shift from the stochastic to deterministic AK stages, which is defined as “economic regress”.     

Stochastic Cooperative Games: Superadditivity, Convexity, and Certainty Equivalents

This paper extends the notions of superadditivity and convexity to stochastic cooperative games. It is shown that convex games are superadditive and have nonempty cores, and that these results also hold in the context of NTU games. Furthermore, a subclass of stochastic cooperative games to which one can associate a deterministic cooperative game is considered. It is shown that such a stochastic cooperative game satisfies properties like nonemptiness of the core, superadditivity, and convexity if and only if the corresponding deterministic game satisfies these properties.Journal of Economic LiteratureClassification Number: C71.     

Ergodic chaos, learning and sunspot equilibrium

Summary. In this paper we construct sunspot equilibria that arise from chaotic deterministic dynamics. These equilibria are stationary and have absolutely continuous stationary measures. We prove that they can be learned by a simple rule based on the histograms of past state variables. This work gives a theoretical justification for complex deterministic models that might compete with stochastic models to explain real data. Also we prove the stochastic stability of the indeterminate equilibrium.     

Optimal delegation with multi-dimensional decisions

This paper investigates optimal mechanisms in a principal–agent framework with a two-dimensional decision space, quadratic payoffs and no monetary transfers. If the conflicts of interest between the principal and the agent are different on each dimension, then delegation is always strictly valuable. The principal can better extract information from the agent by using the spread between the two decisions as a costly screening device. Delegation sets no longer trade off pooling intervals and intervals of full discretion but instead take more complex shapes. We use advanced results from the calculus of variations to ensure existence of a solution and derive sufficient and necessary conditions for optimality. The optimal mechanism is continuous and deterministic. The agent?s informational rent, the average decision and its spread are strictly monotonic in the agent?s type. The comparison of the optimal mechanism with standard one-dimensional mechanisms shows how cooperation between different principals controlling various dimensions of the agent?s activities facilitates information revelation.     

Bubbles in Stochastic Economies: Can They Cure Overaccumulation of Capital?

It is well known that bubbles possess the potential to increase economic welfare due to a reduction of capital accumulation in deterministic overlapping generations economies that are in a dynamically inefficient state. However, actual economies are stochastic, where the concept of dynamic efficiency has turned out to be a complex issue. This paper contributes in two ways. First, the model presented in this paper establishes that dynamic inefficiency is not a necessary condition for deterministic bubbles in a stochastic economy. Second, a simulation shows that although bubbles are unable to persist in the stochastic steady state, they can still cure overaccumulation of capital for a time long enough to cover agents relevant time horizon.     

Optimal climate change mitigation under long-term growth uncertainty: Stochastic integrated assessment and analytic findings

Economic growth over the coming centuries is one of the major determinants of today׳s optimal greenhouse gas mitigation policy. At the same time, long-run economic growth is highly uncertain. This paper is the first to evaluate optimal mitigation policy under long-term growth uncertainty in a stochastic integrated assessment model of climate change. The sign and magnitude of the impact depend on preference characteristics and on how damages scale with production. We explain the different mechanisms driving optimal mitigation under certain growth, under uncertain technological progress in the discounted expected utility model, and under uncertain technological progress in a more comprehensive asset pricing model based on Epstein–Zin–Weil preferences. In the latter framework, the dominating uncertainty impact has the opposite sign of a deterministic growth impact; the sign switch results from an endogenous pessimism weighting. All of our numeric scenarios use a DICE based assessment model and find a higher optimal carbon tax than the deterministic DICE base case calibration.     

A cost function approach to the estimation of minimum efficient scale,returns to scale,and suboptimal capacity: With an application to Canadian manufacturing

This paper presents a new method for utilizing the statistical cost technique to measure minimum efficient scale (MES), returns to scale and suboptimal capacity. An application of the duality theory between cost and homothetic production functions leads to justification for ignoring poor quality or unavailable capital data and the pooling of several years observations to improve the efficiency of the estimates. The methodology is applied to 91 four-digit Canadian manufacturing industries to obtain estimates of MES, returns to scale, and suboptimal capacity. For a subsample of industries, we demonstrate that the cost function estimates of MES and returns to scale are more closely related to engineering estimates than are the ad hoc estimates usually found in the industrial organization literature.     

Reputation building in a monetary policy game

This paper examines the notion of reputation building on the part of the central bank as a means of eliminating socially suboptimal inflation rates that arise in monetary policy games. The framework developed here explicitly models the behavior of wage setters, and it is shown that in the Nash equilibrium these private agents do not attain their desired outcome. Hence, wage setters have an incentive for engaging in a reputation-building game with the central bank. In this game, wage setters are allowed to select “optimally” a reputation based wage strategy, thereby making the strategy choice endogenous. This framework thus lays the groundwork for models in which the private sector behaves as a strategic player. It is shown that there exists a wage contract resembling an indexing arrangement which eliminates the suboptimal inflation rate. Finally, a discussion on the ways of restricting the number of permissible solutions to this game is presented.     

Optimal private good allocation: The case for a balanced budget

In an independent private value auction environment, we are interested in strategy-proof mechanisms that maximize the agents' residual surplus, that is, the utility derived from the physical allocation minus transfers accruing to an external entity. We find that, under the assumption of an increasing hazard rate of type distributions, an optimal deterministic mechanism never extracts any net payments from the agents, that is, it will be budget-balanced. Specifically, optimal mechanisms have a simple “posted price” or “option” form. In the bilateral trade environment, we obtain optimality of posted price mechanisms without any assumption on type distributions.     

The stock market and the vacancy rate

This paper analyzes the vacancy rate in competivive markets. It is shown that the competitive vacancy rate is suboptimal and that it can be higher or lower than the optimal rate.     

Comparing random and deterministic time series

Summary This paper addresses the question of distinguishing the output of a stochastic process from that of a deterministic process. An impossibility theorem is described which states that time a series resulting from deterministic B-processes is observationally equivalent to, and hence indistinguishable from, the output of a continuous time Markov process on a finite number of states.This is an expanded version of a lecture presented at Cornell University in June, 1992 in a conference honoring Roy Radner on his 65th birthday. I would like to thank the organizers of this conference, especially Mukul Majumdar. The author is partially supported by a grant from the NSF.     

Non-parametric estimation of deterministically chaotic systems

Summary This paper studies theoretical and econometric issues that arise in systems characterized by deterministic chaos. Such systems can arise from standard dynamic economic models and are extensively used in Monte Carlo and other simulation-based statistical procedures which use pseudo-random number generators. The virtues of studying chaotic laws of motion in the space of densities over the state space are shown. A complete characterization of deterministic stationary ergodic processes in that space of densities is suggested and proved when the invariant measure is unknown. The asymptotic properties of the kernel estimators of the stationary density and the law of motion in the density space are studied, and shown to hold for chaotic systems. Small sample behavior for the estimators is subjectively shown to be good even when optimal choices of the kernel and smoothing parameters are not exploited.This paper was presented at the winter meetings of the Econometric Society in Atlanta, December 1989. I am grateful to Bo Honoré, Dale Mortensen, Dan Sullivan and especially to Ian Domowitz for many useful comments on early versions of this paper. The comments of participants at Northwestern, Rochester, and UCSD Econometrics Workshops, and of three anonymous referees, are gratefully acknowledged. Related discussions with William Brock, Lars Hansen and Jeffrey Wooldridge were also very useful. All remaining errors are, of course, my own.     

Exit options in incomplete contracts with asymmetric information

This paper analyzes bilateral contracting in an environment with contractual incompleteness and asymmetric information. One party (the seller) makes an unverifiable quality choice and the other party (the buyer) has private information about its valuation. A simple deterministic exit option contract, which allows the buyer to refuse trade, achieves the first-best in the benchmark cases where either quality is verifiable or the buyer?s valuation is public information. But, when unverifiable and asymmetric information are combined, deterministic contracts are necessarily inefficient. The first-best can be achieved, however, through simple message games with stochastic terms of trade as off-equilibrium outcomes.     

Uncertainty and optimal stabilization policy

The impact of uncertainty on optimal stabilization policies is examined in the context of a simple reduced form model. The major finding of the paper is that, in the presence of instrument costs, the dynamic effects of uncertainty can induce an optimal stochastic policy which is more vigorous than the optimal deterministic policy. This result contrasts with the well-known conclusion for static models that uncertainty typically generates optimal responses equally or less intense than deterministic ones.     

Information acquisition in committees

The goal of this paper is to illustrate the significance of information acquisition in mechanism design. We provide a stark example of a mechanism design problem in a collective choice environment with information acquisition. We concentrate on committees that are comprised of agents sharing a common goal and having a joint task. Members of the committee decide whether to acquire costly information or not at the outset and are then asked to report their private information. The designer can choose the size of the committee, as well as the procedure by which it selects the collective choice, i.e., the correspondence between agents' reports and distributions over collective choices. We show that the ex ante optimal device may be ex post inefficient, i.e., lead to suboptimal aggregation of information from a statistical point of view. For particular classes of parameters, we describe the full structure of the optimal mechanisms.     

A comparison of six sampling schemes for price index construction in a COICOP food group

This article compares the behaviour of sampling techniques for price indices using a scanner data set as a model population. Indices produced by two purposive deterministic cut-off designs and four probabilistic sampling schemes are compared with each other and with the ‘true’ population index from the whole data set. We found that the two deterministic cut-off sampling schemes show much different behaviour from the probabilistic sampling schemes. This is not unexpected, as the former schemes have a very restricted focus with respect to the variety of products. We also found that the probabilistic schemes are generally closer to each other and the ‘true’ value than the deterministic cut-off designs. The jackknife resampling technique is also explored as a means of estimating the SE of the index and compared with the actual results from repeated sampling.     

K-Asymptotics Associated with Deterministic Trends in Integrated and Near-Integrated Processes

Dealing with integrated and near-integrated processes, this paper investigates the validity of regression on deterministic trends of K terms as K becomes large. It is found that the regression tends to be valid in spite of the true process being free from deterministic trends, which implies that the distinction between stochastic and deterministic trends disappears in K -asymptotics of the integrated and near-integrated processes. It is also shown that in K -asymptotics the usual unit root test, based on the model with deterministic trends of K terms, becomes useless against near-integration since the unit root distribution remains unchanged.
JEL Classification Numbers: C12, C15, C22.     

Progressive taxation in sequential decisionmaking: Deterministic and stochastic analysis

This paper investigates the effect of progressive taxation on sequential decisionmaking. The decision is the archetypical problem of capital theory: determining the optimal cutting time for a tree that grows according to either a deterministic or stochastic process. For the deterministic model, the optimal cutting time is unaffected by proportional taxes, but decreases as taxes become more progressive. For the stochastic model, the major finding is that uncertainty can partially offset the inefficiency induced by progressive taxation; when this result holds the government benefits from increased uncertainty whereas the taxpayer is harmed. One noteworthy example of this is when the tree's growth is governed by Brownian motion.