Alan Kirman

École des Hautes Études en Sciences Sociales | EHESS · Centre d'analyse et de mathématique sociales (CAMS)

Holocene climate variability in the Mediterranean Basin is often cited as a potential driver of societal change, but the mechanisms of this putative influence are generally little explored. In this paper we integrate two tools–agro-ecosystem modeling of potential agricultural yields and spatial analysis of archaeological settlement pattern data–in...

Locations of sites with regard to elevation and slope. (JPG)

References for SI. (DOCX)

Holocene temperature and precipitation in the study area averaged across cultural periods. (JPG)

Cultural history of provence. (DOCX)

Managing uncertainties. (DOCX)

Potential pulse productivity of the landscape. (JPG)

Summary W1 values for landscape and exploited fractions. (DOCX)

Comparisons of the W1 means of the exploited fractions for each period to the contemporary landscape (landscape mean of pixelwise means across the period for each pixel), and of each period to every other period. (PDF)

Assessing the implications of paleoclimatic and paleoenvironmental data at temporal and spatial scales that would have directly intersected with human decision-making and activity is a fundamental archaeological challenge. This paper addresses this challenge by presenting a spatial and temporal downscaling method that can provide quantitative high-...

This paper explores the relationship between past climate and prehistoric Mediterranean agriculture by adapting a process-based dynamic vegetation model to estimate potential agricultural productivity under climate scenarios that characterize the extremes of Mediterranean climate in the Holocene. We adapt LPJmL (the Lund-Potsdam-Jena-managed-land m...

It is paradoxical that economists wish to consider the economy as a system which can be studied almost independently of the fact that it is embedded in a much larger socio-economic framework. Our difficulties in analysing and diagnosing economic problems lie, in effect, precisely in the fact that the social system constantly generates feedbacks int...

In this publication, we present the talks given at the first workshop of this series, entitled “Modelling Nature and Society – Can We Control the World?” The workshop took place in the city of Weimar from 30 June to 2 July 2016. Its objective was to provide an overview of current attempts to understand and control complex systems in nature and soci...

This book focuses on how important massive information is and how sensitive outcomes are to information. In this century humans now are coming up against the massive utilization of information in various contexts. The advent of super intelligence is drastically accelerating the evolution of the socio-economic system. Our traditional analytic approa...

Complex systems theory and evolutionary theory hold important insight for economics, yet to date they have played a limited role in shaping modern economic theory. This chapter reviews different notions of equilibrium and explores four distinct areas relevant to the incorporation of evolutionary and complexity ideas into economics, finance, and pol...

In their recent book, Colander and Kupers (2014) argue that viewing the economy as a complex adaptive system should change the way in which we make economic policy. This would necessitate a paradigm shift. Economics has, over time, tried to produce a coherent model to underpin the dominant laissez-faire liberal approach. But we have never proved, i...

This paper explores the relationship between past climate and prehistoric Mediterranean agriculture by adapting a process-based dynamic vegetation model to estimate past agricultural productivity under climate scenarios that characterize the extremes of Mediterranean climate (warm/wet, cool/wet, warm/dry, and cool/dry) in the Holocene. We adapt LP...

Economic theory has developed in such a way as to be consistent with the sociopolitical liberalism which became dominant after the Enlightenment. The doctrine of laissez faire, and the argument that leaving people insofar as possible to their own devices would lead to a socially desirable state was based on the conviction that an Invisible Hand wou...

The financial crisis of 2008 was unforeseen partly because the academic theories that underpin policy making do not sufficiently account for uncertainty and complexity or learned and evolved human capabilities for managing them. Mainstream theories of decision making tend to be strongly normative and based on wishfully unrealistic “idealized” model...

We propose an agent-based computational model to investigate sequential Dutch auctions with particular emphasis on markets for perishable goods and we take as an example wholesale fish markets. Buyers in these markets sell the fish they purchase on a retail market. The paper provides an original model of boundedly rational behavior for wholesale bu...

This paper suggests that we need an alternative approach to economic modeling in general, and macroeconomic modeling in particular, if we are to capture salient characteristics of recent economic developments. Rather than focusing on models built on the basis of isolated, rational, optimizing agents, we should recognize that much simpler individual...

The profession of academic economics has been widely criticized for being excessively dependent on technical models based on unrealistic assumptions about rationality and individual behavior, and yet it remains a sparsely studied area. This volume presents a series of background readings on the profession by leading scholars in the history of econo...

In economics in situations where there is uncertainty one has to attribute some attitude to handling this uncertainty to individuals. The original idea was to assume that “people do not make systematic mistakes” for which Muth coined the term “rational expectations”. This was replaced by a much more formal vision which suggested that people fully u...

Structural changes in an economy or in financial markets can arise as a result of agents adopting rules that appear to be the norm around them. Such rules are adopted by implicit consensus as they turn out to be profitable for individuals. However, as rules develop and spread they may have consequences at the aggregate level which are not anticipat...

There is growing recognition that humans are faced with a critical and narrowing window of opportunity to halt or reverse some of the key indicators involved in the environmental crisis. Given human activities’ scale and impact, as well as the overly narrow perspectives of environmental research's dominant natural sciences, a major effort is necess...

In this paper we argue that if we want to find a more satisfactory approach to tackling the major socio-economic problems we are facing, we need to thoroughly rethink the basic assumptions of macroeconomics and financial theory. Making minor modifications to the standard models to remove “imperfections” is not enough, the whole framework needs to b...

This paper argues that the path followed by modern macroeconomic theory excludes the analysis of major endogenous movements in macroeconomic variables. Rather than persist with models based on the idea that the economy behaves like a rational individual we should build models of the economy as a complex system of interacting agents. Profiting from...

We outline a vision for an ambitious program to understand the economy and financial markets as a complex evolving system of coupled networks of interacting agents. This is a completely different vision from that currently used in most economic models. This view implies new challenges and opportunities for policy and managing economic crises. The d...

This paper describes the vision of a European Exploratory for economics and finance using an interdisciplinary consortium of economists, natural scientists, computer scientists and engineers, who will combine their expertise to address the enormous challenges of the 21st century. This Academic Public facility is intended for economic modelling, inv...

Macroeconomics has been preoccupied by the analysis of equilibrium states and their properties. It is assumed that there are mechanisms which will always drive the economy to equilibrium, from which it is perturbed only by exogenous shocks. What is needed however, are models which treat the economy as a complex evolving system which may undergo sud...

Economic theory in crisis The current crisis has shown how far macroeconomic theory is from the economic phenomena it is supposed to explain. I give some historical explanations for the development of this gap between theory and reality. Then I discuss the solidity of the foundations of the general equilibrium model and of the basic model in financ...

The current crisis has shown how far macroeconomic theory is from the economic phenomena it is supposed to explain. I give some historical explanations for the development of this gap between theory and reality. Then I discuss the solidity of the foundations of the general equilibrium model and of the basic model in financial economics and the reas...

The Erasmus Journal for Philosophy and Economics was delighted to have the opportunity to interview Professor Kirman when he visited the Erasmus Institute for Philosophy and Economics (EIPE) in late November 2010 to present a paper on the state of macroeconomics. In this interview, Professor Kirman discusses his understanding of the relationship be...

This paper examines the process by which agents learn to act in economic environments. Learning is particularly complicated in such situations since the environment is, at least in part, made up of other agents who are also learning. At best, one can hope to obtain analytical results for a rudimentary model. To make progress in understanding the dy...

In this paper we analyze the Ancona wholesale fish market (MERITAN) where transactions take place in three simultaneous Dutch auctions. Our objective is to characterize the behavior of market participants and, in particular, that of buyers in such a market structure. Our analysis shows that buyer-seller relationships are less important than in a pa...

This work introduces a special issue of the Journal of Economic Behavior and Organization on the emergence and impact of market institutions in wholesale fish markets. The analysis of fish markets has a respectable pedigree also in terms of the description of how they function. A major advantage of the analysis of fish markets in this literature is...

We study the wholesale fish market in Marseille. Two of the stylized facts of that market are high loyalty of buyers to sellers, and persistent price dispersion, although the same population of sellers and buyers meets in the same market hall on every day. We build a minimal model of adaptive agents. Sellers decide on quantities to supply, prices t...

This paper discusses modern macroeconomic and financial models in the light of the current crisis. Theory has been revealed to be inadequate in its explanation of the origins and the nature of the crisis, as Jean-Claude Trichet the Governor of the European Central bank and his colleagues at other central banks have indicated. Basic macroeconomic mo...

Ce papier, préparé pour un symposium en l'honneur de Marc Barbut, discute des thèmes qui ont lié ses intérêts intellectuels et ceux de son laboratoire le CAMS aux thèmes de l'économie. En particulier il s'agit de l'historique de la notion de marchés efficaces et le refus systématique de la profession économique d'écouter les avertissements de Poinc...

What I argue in this paper is that the direction economics ,and particularly theoretical economics, took in the 20th century was to a great extent due to Walras' influence. This was not so much the result of his own results but rather a reflection of his vision. He was convinced that economics should have “sound mathematical foundations” and his co...

This article examines, in the light of recent events, the origins of the difficulties that current macroeconomic models have in encompassing the sort of sudden crisis which we are currently observing. The reasons for this are partly due to fundamental problems with the underlying General Equilibrium theory and partly to the unrealistic assumptions...

The economic agent is almost by definition considered to be purely self-interested. But even more than this, his utility is defined over what he consumes and in this he is monotonic. We refer to this as being “selfish”. In this paper we investigate the claim that markets make people selfish. We first argue that economic theory allows us to consider...

The authors of the article claim that the economics profession appears to have been unaware of the long build-up to the current worldwide financial crisis and to have significantly underestimated its dimensions. In their view, this lack of understanding is due to a misallocation of research efforts in economics. They trace the deeper roots of this...

This short paper argues that rationally motivated coordination between agents is an important ingredient to understand the current economic crisis. We argue that changes in parameters that model the structure of a macro-economy or financial markets are not exogenous but arise as agents adopt rules that appear to be the norm around them. For example...

The relationship between emotions and rationality is one that has preoccupied man for thousands of years. As the ancient Stoics said, the emotions typically involve the judgement that harm or benefit is at hand ([Sorabji 2006][1]). Already, then, there was thought to be a relationship between

Empathy is a longstanding issue in economics, especially for welfare economics, but one which has faded from the scene in recent years. However, with the rise of neuroeconomics, there is now a renewed interest in this subject. Some economists have even gone so far as to suggest that neuroscientific experiments reveal heterogeneous empathy levels ac...

To date, experiments in economics are mainly restricted to settings in which individuals are not influenced by the physical presence of other people. Interactions remain at a somewhat abstract level with bodily signals being left out of the picture. However, in real life, how many times have we experienced the feeling that trusting someone will be...

The fundamental failing of modern economics, or at least of its dominant mainstream project, is not that it was unable successfully to predict the recent crisis but that it is ill-equipped to illuminate much that happens in the economy at any time. The latter is an assessment that I have advanced and defended on numerous occasions (e.g., Lawson, 19...

Improving the Training of University Students in Economics In France today we are faced with three problems in training young economists. Firstly we have a system in which every university is supposed to offer equivalent degrees and this means that more than half of the students disappear without getting a degree. We cannot offer the sort of course...

Economists not only failed to anticipate the financial crisis; they may have contributed to it—with risk and derivatives models that, through spurious precision and untested theoretical assumptions, encouraged policy makers and market participants to see more stability and risk sharing than was actually present. Moreover, once the crisis occurred,...

In France today we are faced with three problems in training young economists. Firstly we have a system in which every university is supposed to offer equivalent degrees and this means that more than half of the students disappear without getting a degree. We cannot offer the sort of courses which would be appropriate for different types of student...

The economics profession appears to have been unaware of the long build-up to the current worldwide financial crisis and to have significantly underestimated its dimensions once it started to unfold. In our view, this lack of understanding is due to a misallocation of research efforts in economics. We trace the deeper roots of this failure to the p...

Networks of social and economic interactions are often influenced by unobserved structures among the nodes. Based on a simple model of how an unobserved community structure generates networks of interactions, we axiomatize a method of detecting the latent community structures from network data. The method is based on maximum likelihood estimation.

The basic reciprocity between individual parts and collective organization constitutes a key scientific question spanning the biological and social sciences. Such reciprocity is accompanied by the absence of direct linkages between levels of description giving rise to what is often referred to as the aggregation or nonequivalence problem between le...

Our work is part of a quite general research in contemporary economics which focuses on the understanding the emergence of behavioural patterns on markets (KV01) (MR08). In particular, we wish to produce and analyse data that emerge from very simple microbehaviours of sellers in a decentralized economy facing local demand curves. The model we build...

This paper suggests that people can learn to behave in a way which makes them unlucky or lucky. Learning from experience will lead them to make choices which may lead to "luckier" outcomes than others. By so doing they may reinforce the choices of those who find themselves with unlucky outcomes. In this situation, people have reasonably learned to...

This paper, on behalf of the UK-based Association for Heterodox Economists (AHE), argues for a reformulation of the Subject Benchmark Statement for Economics (SBSE) on pluralist principles. Pluralism – the capacity to examine critically a range of explanations for observed reality – should be the primary required outcome of economics education....

Nous comparons � l'aide d'un mod�le multi-agents deux types d'organisations fr�quemment rencontr�es dans les march�s de biens p�rissables: les ench�res simultan�es descendantes ou ench�res hollandaises, et la n�gociation de gr� � gr� sans prix affich�s ; Notre approche consiste � �tudier des populations d'agents artificiels -acheteurs et vendeurs-...

We analyse the interaction between a seller and customers in a shop on the fruits and vegetables wholesale market in Marseille using an unique data set. We find that customers' bargaining activity is correlated with the kind and location of the business. To determine how the interactions between the seller and the customers influence prices, we com...

In this article we examine social neuroeconomics from a complex systems point of view, that is rooted in the theory and methods of informationally coupled self-organizing dynamical systems. Our contribution focuses on establishinng a theoretical perspective within which one can interpret experiments recently published in the field of neuroeconomics...

This paper argues that macro models should be as simple as possible, but not more so. Existing models are “more so” by far. It is time for the science of macro to step beyond representative agent, DSGE models and focus more on alternative heterogeneous agent macro models that take agent interaction, complexity, coordination problems and endogenous...

Economics models markets as mechanisms linking anonymous and otherwise isolated individuals through the price system. Little attention is paid to how these markets are organised nor as to how agents interact within them. In particular it is interesting to know how agents following rather simple rules come to coordinate. This paper discusses the mod...

Complex systems are composed of particles or agents which interact directly with each other. The rules for this interaction may be very simple and may not reflect the sort of rationality associated with standard economic models. Interaction is not through some exogenously given market, nor does it depend on the complicated reasoning involved in gam...

Antonelli was born near Pisa in 1858. He studied mathematics and then went on to qualify as an engineer. Although his life was devoted to civil engineering, he made an important contribution to early mathematical economics. His Sulla teoria matematica dell’economia politica (1886), intended to be the first part of a book, is remarkable, in particul...

Pareto made major contributions to a wide range of subjects covering mathematical economics, statistics, sociology and many others. In economics his name is mainly associated with general equilibrium, welfare economics and ordinal utility. Yet he insisted on the need to confront economic theories with empirical data as his work on income distributi...

Measure theory is that part of mathematics which is concerned with the attribution of weights of ‘measure’ to the subsets of some given set. Such a measure is required to satisfy a natural condition of additivity, that is that the measure of the union of disjoint sets should be equal to the sum of the measure of those sets. The fundamental problems...

Graphs are used in economics to depict situations in which agents are in direct contact with each other. The use of graph theory enables one to understand the basic properties of the communication network in an economy or market. Typical questions include: how does the structure of a network affect economic outcomes and the welfare of the individua...

We consider a model in which foreign and domestic traders buy the assets of both of two countries. Speculators in both countries use chartist or fundamentalist rules for forecasting the exchange rate. Demand for the assets of each country is determined by these forecasts. Perceptions of the fundamentals in each country are not necessarily the same....

Homo Economicus has progressed from an atomistic and self-interested individual in standard economics to a socially embedded agent in modern economics who is endowed with a particular social identity or with specific preferences for the latter. While this vision makes the economic agent more realistic, its representation by adding variables in an a...

Self-organization in socio-economic systems that are complex adaptive systems can follow from simple rule following at a local level. This may be necessary because of outright non-computability issues that arise either due to the logical impossibility of knowledge of the payoff functions based on the full network structure or because the problem is...

Mirowski has put forward an argument for viewing the economy as a set of interlocking markets. I argue that he is right to shift attention from the individual to a higher level. He further holds that there has been a shift to considering the informational problem as central to economics and that this can provide the framework for a new vision of ma...

We study the formation of social networks that are based on local interaction and simple rule following. Agents evaluate the profitability of link formation on the basis of the Myerson-Shapley principle that payoffs come from the marginal contribution they make to coalitions. The NP-hard problem associated with the Myerson-Shapley value is replaced...

Standard macroeconomics, based on a reductionist approach centered on the representative agent, is badly equipped to explain the empirical evidence where heterogeneity and industrial dynamics are the rule. In this paper we show that a simple agent-based model of heterogeneous financially fragile agents is able to replicate a large number of scaling...

We show that a class of microeconomic behavioral models with interacting agents, derived from Kirman (1991) and Kirman (1993), can replicate the empirical long-memory properties of the two first-conditional moments of financial time series. The essence of these models is that the forecasts and thus the desired trades of the individuals in the marke...

In physical models it is well understood that the aggregate behaviour of a system is not in one to one correspondence with the behaviour of the average individual element of that system. Yet, in many economic models the behaviour of aggregates is thought of as corresponding to that of an individual. A typical example is that of public goods experim...

Social and economic networks are becoming increasingly popular in the last ten years, because of both the application of game theory to the network formation processes4, and the study of stochastic processes that fit the statistical properties of real world social networks.5 In the very recent years there have also been attempts to combine the cont...

The industrial dynamic literature has shown the existence of some stylized facts regarding firms’ distribution among which a very important one, for the reasons discussed in the paper, is the scaling law of firms’ size (Axtell, 2001)1.

There are a number of salient features of financial time series, which are hard to explain with standard analysis. The efficient markets hypothesis as well as the idea of rational expectations, seem to be incompatible with the presence of "bubbles" and "herding" behaviour in financial markets, The existence of long memory in financial price series...