Introduction: methodologies of bounded rationality

The modelling of bounded rationality is currently pursued by approaches that exhibit a wide diversity of methodologies. This special issue collects five contributions that discuss different methodological aspects of these approaches. In our introduction, we map the variety of methodological positions with respect to three questions. First, what kinds of evidence do the respective approaches consider relevant for modelling bounded rationality? Second, what kind of modelling desiderata do the respective approaches focus on? And third, how do the respective approaches justify the normative validity of bounded rationality? To broaden the picture, we not only discusss the five contributions of this issue, but also include relevant positions from the extant literature.     

Welfare economics and bounded rationality: the case for model-based approaches

In this paper, we examine the problems facing a policy maker who observes inconsistent choices made by agents who are boundedly rational. We contrast a model-less and a model-based approach to welfare economics. We make the case for the model-based approach and examine its advantages as well as some problematic issues associated with it.     

Sen’s criticism of revealed preference theory and its ‘neo-samuelsonian critique’: a methodological and theoretical assessment

This paper evaluates how Amartya Sen’s critique of revealed preference theory (RPT) stands against the latter’s contemporary, ‘neo-Samuelsonian’ version. Neo- Samuelsonians have argued that Sen’s arguments against RPT are innocuous, in particular once it is acknowledged that RPT does not assume away the existence of motivations or other latent psychological or cognitive processes. Sen’s claims that preferences and choices need to be distinguished and that external factors need to be taken into account to analyze the act of choice then appear to be irrelevant. However, while it is true that contemporary revealed preference theory (CRPT) partially evades Sen’s critique, I show that the latter is still relevant outside the restricted areas of consumer choice and market dynamics. In particular, Sen’s views regarding the importance of incomplete preferences and the multiplicity of levels of agency can hardly be integrated into the framework of CRPT. This is a significant limit, given the imperialistic claims of some of the proponents of the latter.     

Beauty contest,bounded rationality,and sentiment pricing dynamics

We present a dynamic asset pricing model that incorporates investor sentiment, bounded rationality and higher-order expectations to study how these factors affect asset pricing equilibrium. In the model, we utilize a two-period trading market and investors make decisions based on the heterogeneous expectations principle and the “sparsity-based bounded rational” sentiment. We find that bounded rationality results in mispricing and reduces it in next period. Investor sentiment produces more significant effects than private signals, optimistic investor sentiment increases hedging demand, thus causing prices to soar. Higher-order investors are more rational and attentive to the strategies of other participants rather than private signals. This model also derives the dampening effect of higher-order expectations to price volatility and the heterogeneity expectation depicts inconsistent investor behavior in financial markets. In the model, investors' expectations about future price is distorted by their sentiment and bounded rationality, so they obtain a biased mean from the signal extraction.     

A cognition paradigm clash: Simon,situated cognition and the interpretation of bounded rationality

Simon’s notion of bounded rationality is deeply intertwined with his activity as a cognitive psychologist and founder of so-called cognitivism, a mainstream approach in cognitive psychology until the 1980s. Cognitivism, understood as ‘symbolic information processing,’ provided the first cognitive psychology foundation to bounded rationality. Has bounded rationality since then fully followed the development of cognitive psychology beyond symbolic information processing in the post-Simonian era? To answer this question, this paper focuses on Simon’s opposition during the 1990s to a new (paradigmatic) view of cognition called situated cognition, which has since put into question the entire view in cognitive psychology of humans as symbolic information processors. This paper then reads the cognitivism/situated cognition debate through the lens of current bounded rationality research in economics, in order (i) to inquire into whether it has tackled the issues in that controversy; (ii) to envisage possible new foundations for a cognitive psychology-based bounded rationality.     

从经济理性到有限理性:经济学研究理性假设的演变

"经济理性"是经济学的传统研究假设,却因背离现实而受到质疑.基于行为人稀缺的心理资源和系统固有的不确定性而产生的"有限理性"正逐步取代"经济理性"成为经济学研究的理性假设.不同的理性观点可以从决策的视角得到系统地解释和比较.并且,随着理性假设的演变,经济行为的决策标准也相应从单一静态最优向多元动态平衡转变.     

Rationality without Transitivity

In this article rational choice behavior is investigated without assuming transitivity or completeness of the underlying preferences. These standard properties are replaced by a property concerning dominant alternatives. This permits the existence of preference cycles among alternatives which are dominated, while still ensuring the existence of a rational choice correspondence. We will also realize that some rational choice rules still hold in this context. Further we will see that in equilibrium analysis the existence of a competitive equilibrium follows when transitivity and completeness is replaced by this domination property.     

Normative ecological rationality: normative rationality in the fast-and-frugal-heuristics research program

The purpose of this paper is to examine the normative interpretation of the fast-and-frugal research program and in particular to contrast it with the normative reading of rational choice theory and behavioral economics. The ecological rationality of fast-and-frugal heuristics is admittedly a form of normative naturalism (Gigerenzer and Sturm 2012) – it derives what agents “ought” to do from that which “is” ecologically rational – and the paper will examine how this differs from the normative rationality associated with rational choice theory. I will also attempt to assess the relative adequacy of normative ecological rationality.     

Why rationality is not a consequence of Hume's theory of choice

This paper argues that the theory of action proposed by Hume in the Treatise does not imply that individuals are rational in the sense of modern choice theory. An individual's behaviour is non-rational if his/her choices systematically contravene the consistency axioms of the theory, and if the causal explanation of those choices cannot credibly be offered as a reason for making them. Hume proposes a theory of causal relationships between mental states, based on associations of ideas. The relationships he postulates are liable to induce various forms of non-rational behaviour, some of which have since been observed in controlled experiments.     

The road to rationalisation: A history of “Where the Empirical Lives” (or has lived) in consumer choice theory

This paper examines the different ways that economists have characterised the empirical content of modern consumer choice theory. There has been general agreement among economists that each stage in the development of the theory has been associated with an improvement in the theory's empirical content, and yet there has been no agreement about what exactly the empirical content of consumer choice theory is at any stage in the process. I call this the problem of observational ambiguity. The paper historically documents this problem, links it to various theoretical developments, and relates it to debates in contemporary economic theory.     

Why rationality may be a consequence of Hume's theory of choice

Facing R. Sugden's criticism of our interpretation, it is shown in this paper that rationality appears as a possible consequence of Hume's theory of choice. We first argue that Sugden's dismissal of the preference relation from the type of rationality through which Hume's theory is apprehended, is highly disputable, from the point of view of both standard choice theory and Hume's theory of passions. Nonetheless, Sugden's criterion of rationality might be restated in Humean terms as a condition of non-revision of preferences in the dynamics of passions. But, since the process of choice that we have described explicitly takes into account the revision of preferences, and shows that, when this last is no longer required, rationality occurs as an outcome of this process, it is not really concerned by Sugden's criticism.     

A Humean theory of choice of which rationality may be one consequence

For the reader who considers economic theory of choice as a special case of a more general theory of action, Hume's discussion of the determinants of action in the Treatise of Human Nature (1739?–?40), in the Enquiry on Human Understanding (1748) and in the Dissertation on Passions (1757) deserves attention. However, according to some modern commentators, Hume does not seem to have given any evidence that would favour what nowadays we would consider as the kind of rationality involved in modern theories of rational choice. On the contrary, this paper arrives at the conclusion that consistency between preferences and choice, like the usual properties of completeness and transitivity, may be considered as outcomes of a mental process, described by means of a decision algorithm that aims to represent Hume's theory of choice.     

Bounded rationality,neural network and folk theorem in repeated games with discounting

Summary The perfect folk theorem (Fudenberg and Maskin [1986]) need not rely on excessively complex strategies. We recover the perfect folk theorem for two person repeated games with discounting through neural networks (Hopfield [1982]) that have finitely many associative units. For any individually rational payoff vector, we need neural networks with at most 7 associative units, each of which can handle only elementary calculations such as maximum, minimum or threshold operation. The uniform upper bound of the complexity of equilibrium strategies differentiates this paer from Ben-Porath and Peleg [1987] in which we need to admit ever more complex strategies in order to expand the set of equilibrium outcomes.I would like to thank Hao Li and John Curran for excellent research assistance. Financial support from National Science Foundation (SES-9223483), Sloan Foundation and the Division of Social Sciences at the University of Chicago is gratefully acknowledged.     

Global convergence of adaptive learning in models of pure exchange

Summary. This paper develops an adaptive learning scheme for a standard version of the OLG model with pure exchange. Perfect forecasting rules which generate perfect foresight orbits are approximated by cubic spline functions. These approximations are successively constructed using historical data only. Trajectories generated by this scheme converge to perfect foresight orbits globally for all initial conditions. This result holds for all parameterizations guaranteeing the existence of a monetary steady state and hence is independent of consumers' savings behavior. It generalizes to all one-dimensional models of the Cobweb type. Received: October 5, 2000; revised version: February 15, 2001     

On Forecasting Heterogeneity, Irrational Exuberance, and the Multiplicity of Rational Expectations Equilibria

Received February 20, 2001; revised version received July 23, 2001     

Expectations,uncertainty and institutions. An application to the analysis of social security reforms

The aging process that many developed economies will face in the medium-term is leading to reforms in the public pensions systems in order to solve the potential financial unsustainability generated by the foreseeable increase in the expenditure in pension benefits (assuming that the current social security contributions and the eligibility conditions will remain unchanged). Neoclassical economics defends a radical reform of these systems, substituting the current pay-as-you-go (PAYGO) systems by funded systems. In this paper, using the Post-Keynesian theory as a theoretical framework, we provide an alternative reflection to that proposed by the neoclassical economics about the choice between the alternative pension systems. The focus of the paper is the advantages of the PAYGO pension systems to stabilize the expectations of future income.     

宏观经济政策是否有效——基于理性预期模型的分析

自《通论》发表以来,关于宏观经济政策是否有效的争论一直贯穿于整个宏观经济学界。因此,从理性预期模型出发,对于宏观经济政策是否有效进行了再分析,通过博弈论思想的引入探究了宏观经济政策能否达到理想效果。在对扩张性宏观经济政策实际效果进行分析时指出了为何会出现“滞涨”,为何近年中国经济能够实现高增长低通胀的问题。     

风险度量的经济学理性与风险度量方法比较

本文引入风险度量的经济学理性概念:一种风险度量方法为经济学理性的是指,这种方法对风险的度量结果与经济学中理性人对风险的排序结果相一致,采用这种方法度量风险的决策者,其决策结果也是经济学理性的。本文从风险状态下的决策理论出发,论证了在银行监管问题上,经济学理性的风险度量方法需要满足的条件。结合银行资本充足率监管的演进趋势,比较了几种重要的风险度量方法,并提出了一种经济学理性的、符合银行监管需要的风险度量方法。     

Low information nash equilibria for oligopolistic markets

This paper deals with an infinite horizon n firm oligopoly in which firms are assumed to have incomplete information about one another's actions and profit functions. An equilibrium concept is defined that is similar to the Nash non-cooperative equilibrium, but is suitable for the information assumptions of the model. The equilibrium uses a type of bounded rationality which makes firms' computations relatively easy. This is due to an implicit assumption that computation is costly and a Bayesian approach is prohibitively costly. This low information Nash equilibrium is proved to exist, and, in addition, an adaptive expectations decision process is described which, if followed by all firms, leads to the low information Nash equilibrium.     

What kind of preference maximization does the weak axiom of revealed preference characterize?

A (multivalued) choice is justified if no two chosen alternatives are preferred to each other, and if all chosen alternatives are preferred to all rejected alternatives. This concept permits a connection between the behavioral property expressed by WARP and a weak form of preference maximization. I am grateful to Michele Lombardi, Michael Mandler, Paola Manzini and an anonymous referee for useful discussions and comments.