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on Evolutionary Economics |
| By: | Kevin Marechal (Centre Emile Bernheim, Solvay Business School, Université Libre de Bruxelles, Brussels and CEESE, Université Libre de Bruxelles.); Hélène Aubaret-Joachain (Institut pour un Développement durable, Ottignies, Belgique); Jean-Paul Ledant (Institut pour un Développement durable, Ottignies, Belgique) |
| Abstract: | Putting agricultural systems on a more sustainable path is a crucial policy issue. Within that context, the objective of this paper is to show how the unsustainable character of current agricultural systems is strongly related to the prevailing rationale of mainstream economics and the Cartesian-Newtonian worldview on which it is founded. Using the example of the transformation of post-war agriculture in France, our analysis underlines the profound influence of the logic of mainstream economics on the modernisation of agricultural systems. The resulting transformation of agricultural systems based on the triptych specialisation-intensification-concentration is then further explored regarding its negative impacts in terms of sustainability. Particular attention is dedicated to environmental impacts, given their magnitude and the fact that mainstream economics, because of its “mechanistic reductionist” framework, has intrinsic difficulties in dealing with them. Since the fundamental assumptions of mainstream economics are being strongly challenged, it becomes legitimate to resort to an alternative economic framework for designing appropriate policies and measures. Given that many empirical studies demonstrates that agricultural systems may be locked-in to some extent, the choice an evolutionary line of thought in an ecological perspective is quite straightforward. This approach of economic change both underlines its historically-contingent nature and the role played by systemic interdependencies. Through underlining the path-dependence of agricultural systems, the use of the evolutionary framework in an ecological perspective allows us to shed a new light on their transformation by suggesting some strategies (i.e. niche accumulation and hybridisation) that have proven efficient in overcoming cases of lock-in in other fields. |
| Keywords: | Agricultural systems; Mechanistic reductionism; Evolutionary economics; Path-dependence and lock-in; Environmental pressures |
| Date: | 2008–10 |
| URL: | http://d.repec.org/n?u=RePEc:sol:wpaper:08-028&r=evo |
| By: | De Marco, Giuseppe; Romaniello, Maria |
| Abstract: | In Hart and Kurz (1983), stability and formation of coalition structures has been investigated in a noncooperative framework in which the strategy of each player is the coalition he wishes to join. However, given a strategy profile, the coalition structure formed is not unequivocally determined. In order to solve this problem, they proposed two rules of coalition structure formation: the $\gamma$ and the $\delta$ models. \par In this paper we look at the evolutionary games arising from the $\gamma$ and $\delta$ models in which players determine at every instant their strategies and, in particular, we study how the coalition structure evolve according to the strategic choices. For this purpose we consider mixed strategies and, firstly, we notice that natural generalizations of the $\gamma$ and $\delta$ models to this case lead to multiplicity of beliefs (on the set of coalition structures) coherent with the probability assignments given by the strategy profile. Coherency is regarded as a viability constraint for the differential inclusions describing the evolutionary games. Therefore, we investigate viability properties of the constraints and characterize velocities of pairs belief/strategies which guarantee that coherency of beliefs is always satisfied. Finally, among many coherent belief revisions (evolutions), we investigate those characterized by minimal change and provide existence results. |
| Keywords: | Coalition formation; coherent beliefs; differential inclusions; viability theory; minimal change belief revision |
| JEL: | D71 C71 D83 C72 C73 |
| Date: | 2008–03–26 |
| URL: | http://d.repec.org/n?u=RePEc:pra:mprapa:10923&r=evo |
| By: | Smith, Peter |
| Abstract: | Fuzzy logic and genetic algorithms are used to rework more realistic (and more complex) models of competitive markets. The resulting equilibria are significantly different from the ones predicted from the usual static analysis; the methodology solves the Walrasian problem of how markets can reach equilibrium, starting with firms trading at disparate prices. The modified equilibria found in these complex market models involve some mutual self-restraint on the part of the agents involved, relative to economically rational behaviour. Research (using similar techniques) into the evolution of collaborative behaviours in economics, and of altruism generally, is summarized; and the joint significance of these two bodies of work for public policy is reviewed. The possible extension of the fuzzy/ genetic methodology to other technical aspects of economics (including international trade theory, and development) is also discussed, as are the limitations to the usefulness of any type of theory in political domains. For the latter purpose, a more differentiated concept of rationality, appropriate to ill-structured choices, is developed. The philosophical case for laissez-faire policies is considered briefly; and the prospects for change in the way we ‘do economics’ are analysed. |
| Keywords: | Fuzzy logic; genetic algorithms; complexity; emergence; rationality; ill-structured choice; equilibrium; Walrasian Crier; paradigm change; |
| JEL: | B0 C61 B41 |
| Date: | 2008–10–02 |
| URL: | http://d.repec.org/n?u=RePEc:pra:mprapa:10899&r=evo |
| By: | Gabriella Dellino; Mariagrazia Fedele; Carlo Meloni |
| Abstract: | Several approaches for solving multi-objective optimization problems entail a form of scalarization of the objectives. This paper proposes a study of different dynamic objectives aggregation methods in the context of evolutionary algorithms. These methods are mainly based on both weighted sum aggregations and curvature variations. A comparison analysis is presented on the basis of a campaign of computational experiments on a set of benchmark problems from the literature. |
| Keywords: | Multi-objective optimization, Evolutionary algorithms, Aggregate objective functions |
| Date: | 2008–03 |
| URL: | http://d.repec.org/n?u=RePEc:ufg:qdsems:06-2008&r=evo |