Nonparametric learning rules from bandit experiments: The eyes have it!

How do people learn? We assess, in a model-free manner, subjectsʼ belief dynamics in a two-armed bandit learning experiment. A novel feature of our approach is to supplement the choice and reward data with subjectsʼ eye movements during the experiment to pin down estimates of subjectsʼ beliefs. Estimates show that subjects are more reluctant to “update down” following unsuccessful choices, than “update up” following successful choices. The profits from following the estimated learning and decision rules are smaller (by about 25% of average earnings by subjects in this experiment) than what would be obtained from a fully-rational Bayesian learning model, but comparable to the profits from alternative non-Bayesian learning models, including reinforcement learning and a simple “win-stay” choice heuristic.     

Farsightedly stable networks

A set of networks G is pairwise farsightedly stable (i) if all possible farsighted pairwise deviations from any network g∈ G to a network outside G are deterred by the threat of ending worse off or equally well off, (ii) if there exists a farsighted improving path from any network outside the set leading to some network in the set, and (iii) if there is no proper subset of G satisfying conditions (i) and (ii). A non-empty pairwise farsightedly stable set always exists. We provide a full characterization of unique pairwise farsightedly stable sets of networks. Contrary to other pairwise concepts, pairwise farsighted stability yields a Pareto dominant network, if it exists, as the unique outcome. Finally, we study the relationship between pairwise farsighted stability and other concepts such as the largest pairwise consistent set and the von Neumann–Morgenstern pairwise farsightedly stable set.     

Pairwise epistemic conditions for Nash equilibrium

We introduce a framework for modeling pairwise interactive beliefs and provide an epistemic foundation for Nash equilibrium in terms of pairwise epistemic conditions locally imposed on only some pairs of players. Our main result considerably weakens not only the standard sufficient conditions by Aumann and Brandenburger (1995), but also the subsequent generalization by Barelli (2009). Surprisingly, our conditions do not require nor imply mutual belief in rationality.     

Standards and the regulation of environmental risk

We study regulatory design for a pollution-generating firm who is better informed than the regulator regarding pollution mitigation possibilities, and who chooses an unobservable action when employing a particular mitigation plan. We distinguish among performance, process, and design standards, and study the relative merit of each type of regulatory instrument. Relative to previous work on standards design, we emphasize technology and process verification. An optimal performance standard is relatively strict when regulator and firm preferences are congruent, but the regulator may prefer no performance standard at all if verification costs are sufficiently high. A process standard unambiguously increases expected surplus (relative to no regulation) in some environments, and otherwise improves welfare only when it is unlikely to generate a “bad” technology choice by the firm. A design standard can improve welfare if the regulator is sufficiently well informed about the technological possibilities for pollution control, but only when the firm’s private benefits from technology choice are sufficiently small.     

Probabilistic dominance and status quo bias

Decision makers have a strong tendency to retain the current state of affairs. This well-documented phenomenon is termed status quo bias. We present the probabilistic dominance approach to status quo bias: an alternative is considered acceptable to replace the status quo only if the chances of a (subjectively) severe loss, relative to the status quo, are not too high. Probabilistic dominance is applied and behaviorally characterized in a choice model that allows for a range of status quo biases, general enough to accommodate unanimity, but also standard expected utility maximization. We present a comparative notion of “revealing more bias towards the status quo” and study its implications to the probabilistic dominance model of choice. Lastly, the model is applied to the endowment effect phenomenon and to a problem of international portfolio choice when investors are home biased.     

地理信息系统在区域商业和经济中的应用初探

有效地开发和利用地理空间数据，可以优化配置资源，降低商业运行成本，并规划、监测、改善区域商业和经济环境。而地理信息系统，不仅是关于地理数据的获取、存储、转换、分析和表示的原则、方法和工具，而且提供了认识空间现象的思维方式和解决空间问题的方法，可用于定义、分析、表现复杂的空间经济现象。基于这样的认识，本文试图从理论上探讨地理信息、商业环境和区域经济发展间的关系，并结合中国广东的区域经济状况，初步分析地理信息系统在商业和区域经济中的潜在应用。     

Valuations of aircraft noise: experiments in stated preference

The aim of this paper is to report new evidence relating to residents’ valuations of aircraft noise in three countries with an emphasis on a comparison of the valuations obtained using two contrasting approaches. One might be regarded as a standard stated choice approach offering pairwise comparisons of two alternatives characterised by a limited number of attributes. The other choice format adopted is innovative in drawing inspiration from the priority evaluator approach to embed aircraft movements alongside a wide range of other local factors that impact on residents’ quality of life. The paper addresses the differences in the results of the two approaches and explores the possible explanations for these variations. Although not conclusive, there is a suspicion that strategic bias may have influenced the results and we urge further research regarding incentives to such bias.     

Entrepreneurial strategy v. accounting accuracy in ‘calculating’ capital and income

Both entrepreneurs and accountants ??calculate?? capital and income but their procedures diverge. The paper examines this divergence and the respective calculational objectives of entrepreneurs and accountants in the business enterprise. For the entrepreneur, capital and income are ex ante calculational judgments of prospective income gain from strategic use of the enterprise??s capital goods. But the accountant must shun entrepreneurial judgments to ??calculate?? the contemporary net market value of enterprise??s capital goods at a specified date. Hence, the accountant??s calculation of income is the net contemporary increase in the market value of the enterprise??s capital goods. These accounting calculations facilitate assessment of the success of an enterprise strategy. But critics assert that accounting practice ignores the need of external investor??s for accurate information on enterprise prospects. The paper concludes with a critique of accounting regulation and explores the feasibility and means of privatizing the entrepreneurial choice of accounting techniques.     

Can a larger market foster R&D under monopolistic competition with variable mark-ups?

We study monopolistic competition with symmetric directly additive preferences (generating variable mark-ups) and an endogenous technology choice. Each firm chooses an investment in R&D to decrease its marginal cost. We prove that the equilibrium R&D investment increases with market size (a larger population or trade) only if the price-elasticity of demand is an increasing function. Together with the output levels, such equilibrium investments may be socially excessive or insufficient, depending on whether the elasticity of the subutility is increasing or decreasing. The main implication is that opening up to free trade can foster R&D through variable mark-ups.     

Choice and individual welfare

We propose an abstract method of systematically assigning a “rational” ranking to non-rationalizable choice data. Our main idea is that any method of ascribing welfare to an individual as a function of choice is subjective, and depends on the economist undertaking the analysis. We provide a simple example of the type of exercise we propose. Namely, we define an individual welfare functional as a mapping from stochastic choice functions into weak orders. A stochastic choice function (or choice distribution) gives the empirical frequency of choices for any possible opportunity set (framing factors may also be incorporated into the model). We require that for any two alternatives x and y, if our individual welfare functional recommends x over y given two distinct choice distributions, then it also recommends x over y for any mixture of the two choice distributions. Together with some mild technical requirements, such an individual welfare functional must weight every opportunity set and assign a utility to each alternative x which is the sum across all opportunity sets of the weighted probability of x being chosen from the set. It therefore requires us to have a “prior view” about how important or representative a choice of x at a given situation is.     

Network effects and the choice of mobile phone operator

This paper explores the role of network effects in the consumer’s choice of mobile phone operators in the UK. It contributes to the existing literature by taking a new approach to testing for direct network effects and by using individual-level data, which allows to analyse the impact that the immediate social network has on consumer choice in network markets. For our empirical analysis we use two sources of data: market-level data from the British telecommunications regulator OFCOM and micro-level data on consumers’ usage of mobile telephones from the survey, Home OnLine. We estimate two classes of models which illustrate the role of network effects. The first is an aggregate model of the comparative volume of on-net and off-net calls. This finds that the proportion of off-net calls falls as mobile operators charge a premium for off-net calls, but even in the absence of any price differential between on-net and off-net, there is still a form of pure network effect, where a disproportionate number of calls are on-net. The second is a model of the individual consumer’s choice of operator. This finds that individual choice shows considerable inertia, as expected, but is heavily influenced by the choices of others in the same household. There is some evidence that individual choice of operator is influenced by the total number of subscribers for each operator, but a much stronger effect is the operator choice of other household members.     

Social choice and welfare economics under representative government

In his Impossibility Theorem, Arrow demonstrated logically that certain a priori conditions cannot all be satisfied by a rule of social choice. Those conditions, however, are admittedly value judgments, and how ethically impelling they are remains in dispute. To appraise that matter, the theorem is properly seen in a political context, and Arrow himself has seen it so, but he focuses in effect on ‘direct democracy.’ Further clarification may result from reference instead to different forms of ‘representative government.’ The same inquiry may also illuminate another still controversial matter: the import of the theorem for welfare economics.     

Coding economic dynamics to represent regime dynamics. A teach-yourself exercise

Much of the recent economic history of various countries, regions and/or sectors in the world economy can usefully be reconstructed as sequences of repeated, basically endogenously induced, changes of growth regimes. Coded dynamics (CD) is proposed hereafter as the appropriate tool for the analysis of such multi-regime dynamics, i.e. dynamics where switches between growth regimes represent structural changes, or in other words, abrupt alterations in an economy's qualitative dynamics. On a theoretical tone, one of our arguments in favor of the adoption of a CD approach derives from the lesson that can be drawn from the complex dynamics literature. Often, some form of regularity, while it cannot be found in the punctual analysis of motion across states, can be recovered from the system's dynamics over a partition of its state space. This dynamics can be represented by strings of symbols (instead of real numbers), or symbolic trajectories. The 2-fold purpose of this paper is to introduce the formalism and terminology of multi-regime dynamics, and to try our hand with the technique of coding through a set of simple exercises. In fact, we consider only cases with two and three regimes, instead of the six of the Framework Space introduced in the Preface. Via such exercises, we also trace the origins of the multi-regime framework in the tradition of classical macrodynamics.     

Community standards

I introduce a model of community standards relevant to the judicial determination of obscenity. Standards are defined as subjective judgments restricted only by a simple reasonableness condition. Individual standards are aggregated to form the community standard. Several axioms reflect legal concerns. These require that the community standard (a) preserve unanimous agreements, (b) become more permissive when all individuals become more permissive, and not discriminate, ex ante, (c) between individuals and (d) between works. I show that any rule which satisfies these properties must be “similar” to unanimity rule. I also explore the relationship between the model and the doctrinal paradox of Kornhauser and Sager [12].     

Presidential Address: Mathematics in economics and econometrics

Abstract The paper discusses the choices of mathematical approaches in economics and econometrics, in particular, approaches that either (a) aim for a sharp result or (b) use the least restrictive assumptions. It is argued that, while the choice (a) often necessitates strong mathematical assumptions, choice (b) may lead to only partial identification and may require using less familiar mathematical techniques. This is discussed in the context of the problem of defining a probability density: existence may fail in function spaces; even after imposing assumptions that ensure existence, the problem is not well posed. A density function may not exist for economic variables as a consequence of institutional rigidity such as an income supplement. The apparatus of generalized functions provides the general solution to identification and well‐posedness of density, but at the cost of less sharp results and greater mathematical complexity.     

On efficiency of the English auction

We study efficiency properties of the irrevocable exit English auction in a setting with interdependent values. Maskin (1992) [1] shows that the pairwise single-crossing condition is sufficient for efficiency of the English auction with two bidders and suggests that it is also a necessary condition. This paper clarifies and extends Maskin?s results to the case of N bidders. We introduce the generalized single-crossing condition—a fairly intuitive extension of the pairwise single-crossing condition—and prove that it is essentially a necessary and sufficient condition for the existence of an efficient equilibrium of the N-bidder English auction.     

On the theory of reference-dependent preferences

A theory is proposed in which preferences are conditional on reference points. It is related to Tversky and Kahneman’s reference-dependent preference theory, but is simpler and deviates less from conventional consumer theory. Preferences conditional on any given reference point satisfy conventional assumptions. Apart from a continuity condition, the only additional restriction is to rule out cycles of pairwise choice. The theory is consistent with observations of status quo bias and related effects. Reference points are treated as subject to change during the course of trade. The implications of endogeneity of reference points for behaviour in markets are investigated.     

Rationality,constitutions, and the ethics of rules

It seems clear that individuals stand to mutually benefit, in a wide variety of situations, from structuring their interactions in terms of constitutional practices. But a commitment to treat the rules defining such practices as setting real constraints on choice—a commitment to what could be characterized as an “ethics of rules”—is hard to reconcile with the standard, consequentialist theory of rational choice, which requires, in effect, that individuals regard any rule as providing no more than a “maxim” for choice. Such a theory of rational choice, then, constrains individuals to settle for a second best outcome in which choice is aligned with practice rules by means of strategies of precommitment and threats. The outcome is second best because such methods yield only partial alignment, and involve the expenditure of scarce resources, as well as a sacrifice of flexibility and freedom. To say this, however, is to identify the corresponding theory of rational choice as havingconsequentially unacceptable implications. A modified theory of choice is presented, which is still consequentially oriented, but which assesses consequences in a more holistic manner. It is then argued that this modified theory can provide a rational choice grounding for the needed “ethics of rules.” The author would like to thank three anonymous referees for their very helpful comments and suggestions.     

The effect of individual ‘ability to choose’ (scale heterogeneity) on the valuation of environmental goods

Environmental valuation methods, such as choice experiments, are increasingly being used to value complex and often unfamiliar environmental goods. A potential risk is that some survey respondents may not be capable of developing and expressing preferences for such goods. The noise from these individuals may then conceal the well-defined preferences of other respondents and affect valuation estimates. We address this problem by estimating a range of models that accounts for scale heterogeneity (which we interpret as a respondent's ability to choose: ATC) and taste heterogeneity. These models are applied to two case studies: amenity from coastal defence and biodiversity. In both case studies, model fit was improved in a scale-heterogeneity multinomial-logit (S-MNL) model (compared to a standard MNL model) suggesting the accounting for ATC (scale heterogeneity) improved preference revelation. A mixed multinomial-logit (MIXL) model outperformed the S-MNL model suggesting that accounting for taste heterogeneity was also important. However, a generalised multinomial-logit (G-MNL) model improved model fit over the MIXL model only for the biodiversity data suggesting that for these data both taste heterogeneity and ATC were important. We conclude that accounting for ATC can improve the reliability and robustness of the results when valuing complex or unfamiliar environmental goods.     

New constitutional “debt brakes” for Euroland? A question of institutional complementarity

Despite the EU Stability & Growth Pact and existing constitutional limits on public deficit/debt at the (sub)national level in many EU member countries, in the wake of the 2010 Greek bailout, many politicians and policy advisors have proposed new constitutional “debt brakes” to prevent future fiscal crises and bailouts. This paper puts a question mark behind this popular policy recommendation. Public choice scholars and other critical observers have repeatedly emphasised that constitutional deficit/debt limits are not per se credible commitments to run a sound fiscal policy in the future. To demonstrate this, design defects of such fiscal constraints are usually pointed out (no politically independent control, no sanctions, etc.). Going beyond this standard approach of credibility assessment, this paper argues for taking the issue of institutional complementarity seriously. To assess its credibility, one has to not only examine the design of a deficit/debt limit but also the institutional environment (tax/expenditure policy, capital market, etc.) in which such a constitutional commitment is embedded.