Learning in evolutionary environment

@misc{citeulike:2747760, abstract = {In the most generic terms, learning may occur in all circumstances whereby agents have an imperfect understanding of the world in which they operate - either due to lack of information about it, or, more fundamentally, to an imprecise knowledge of its structure -; or, when they master only a limited repertoire of actions in order to cope with whatever problem they face - as compared to the set of actions that an omniscient observer would be able to conceive -; or, finally, when they have only a blurred and changing understanding of what their goals and preferences are. It is straightforward that learning, so defined, is an ubiquitous characteristic of most economic and, generally, social environments, with the remarkable exception of those postulated by the most extreme forms of economic modelling, such as those assuming rational expectations or canonical game-theoretic equilibria. But, even in the latter cases, - and neglecting any issue of empirical realism of the underlying assumptions -, it is natural to ask how did agents learn in the first place about e.g. the “true model” of the world in a RE set-up, or the extensive form of a particular game? And, moreover, in the widespread case of multiple equilibria, how do agents select among them (i.e. how do they learn how to converge to one of them)? Of course, learning acquires even greater importance in explicitly evolutionary environments (which we believe be indeed the general case), where a) heterogeneous agents systematically display various forms of “bounded rationality”; b) there is a persistent appearance of novelties, both as exogenous shocks, and, more important, as the result of technological, behavioural and organisational innovations by the agents themselves; c) markets (and other interaction arrangements) perform as selection mechanisms; d) aggregate regularities are primarily emergent properties stemming from out-of-equilibrium interactions (more detailed discussions are in Dosi and Nelson (1994), Nelson (1995), Coriat and Dosi (1995b)). The purpose of this work is to present a sort of selective guide to an enormous and diverse literature on learning processes in economics in so far as they capture at least some of the foregoing evolutionary aspects. Clearly, this cannot be a thorough survey. Rather, we shall just refer to some examples of each genre, trying to show their links and differences, setting them against a sort of ideal framework of “what one would like to understand about learning...”. This allows also an easier mapping of a wide and largely unexplored research agenda. A significant emphasis shall be put on learning models, in their bare-bone formal structure, but we shall always refer to the (generally richer) non-formal theorising about the same objects.}, author = {Dosi, Giovanni and Marengo, Luigi and Fagiolo, Giorgio }, citeulike-article-id = {2747760}, comment = {a literature of learning/evolutionary theoryies as of '96}, keywords = {asymmetric, economics, evolution, institutions, intro, learning}, posted-at = {2008-05-03 10:04:03}, priority = {2}, title = {Learning in evolutionary environment}, url = {http://ideas.repec.org/p/trn/utwpce/9605.html} }

TY - ELEC ID - citeulike:2747760 L3 - citeulike-article-id:2747760 TI - Learning in evolutionary environment N2 - In the most generic terms, learning may occur in all circumstances whereby agents have an imperfect understanding of the world in which they operate - either due to lack of information about it, or, more fundamentally, to an imprecise knowledge of its structure -; or, when they master only a limited repertoire of actions in order to cope with whatever problem they face - as compared to the set of actions that an omniscient observer would be able to conceive -; or, finally, when they have only a blurred and changing understanding of what their goals and preferences are. It is straightforward that learning, so defined, is an ubiquitous characteristic of most economic and, generally, social environments, with the remarkable exception of those postulated by the most extreme forms of economic modelling, such as those assuming rational expectations or canonical game-theoretic equilibria. But, even in the latter cases, - and neglecting any issue of empirical realism of the underlying assumptions -, it is natural to ask how did agents learn in the first place about e.g. the “true model” of the world in a RE set-up, or the extensive form of a particular game? And, moreover, in the widespread case of multiple equilibria, how do agents select among them (i.e. how do they learn how to converge to one of them)? Of course, learning acquires even greater importance in explicitly evolutionary environments (which we believe be indeed the general case), where a) heterogeneous agents systematically display various forms of “bounded rationality”; b) there is a persistent appearance of novelties, both as exogenous shocks, and, more important, as the result of technological, behavioural and organisational innovations by the agents themselves; c) markets (and other interaction arrangements) perform as selection mechanisms; d) aggregate regularities are primarily emergent properties stemming from out-of-equilibrium interactions (more detailed discussions are in Dosi and Nelson (1994), Nelson (1995), Coriat and Dosi (1995b)). The purpose of this work is to present a sort of selective guide to an enormous and diverse literature on learning processes in economics in so far as they capture at least some of the foregoing evolutionary aspects. Clearly, this cannot be a thorough survey. Rather, we shall just refer to some examples of each genre, trying to show their links and differences, setting them against a sort of ideal framework of “what one would like to understand about learning...”. This allows also an easier mapping of a wide and largely unexplored research agenda. A significant emphasis shall be put on learning models, in their bare-bone formal structure, but we shall always refer to the (generally richer) non-formal theorising about the same objects. KW - asymmetric KW - economics KW - evolution KW - institutions KW - intro KW - learning N1 - a literature of learning/evolutionary theoryies as of '96 AU - Dosi, Giovanni AU - Marengo, Luigi AU - Fagiolo, Giorgio UR - http://ideas.repec.org/p/trn/utwpce/9605.html ER -