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on Computational Economics |
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Issue of 2007‒10‒27
eight papers chosen by |
| By: | Ch'ng, Kean Siang |
| Abstract: | The paper is about application of evolutionary concept, particularly the application of natural selection process, to the study of movie industry. The importance of the application is that it allows for the heterogeneity and interdependency of market agents in analyzing the economic choice decision. This complexity always presents an obstacle to the study of market behavior, especially when one has to take into account the constant reinforcing effects among the variables, which often renders the problem elusive. The paper intends to explain the economic process, particularly the evolution of exhibition contract, taking into account this complexity through the use of evolutionary concept. |
| Keywords: | Evolutionary selection; opportunity costs; learning and sharing rule. |
| JEL: | D81 B41 L21 |
| Date: | 2007–09–27 |
| URL: | http://d.repec.org/n?u=RePEc:pra:mprapa:5387&r=cmp |
| By: | Ackland, Robert (Australian Demographic and Social Institute, The Australian National University, Canberra, Australia); Shorish, Jamsheed (Department of Economics and Finance, Institute for Advanced Studies, Vienna, Austria) |
| Abstract: | The political blogosphere has recently been the focus of attention for social network analysis and applications of network and graph theory. In a recent paper, Adamic and Glance (2005) report differences between the linking behavior of politically conservative vs. politically liberal Web bloggers. We construct a simple agent-based network formation model which shows that one such difference, demonstrating what we term ‘political homophily’, can be generated by connecting the blogosphere to the underlying population distribution of political preferences. The model is implemented as a web service in the e-tool VOSON (Virtual Observatory for the Study of Online Networks), and both model and tool serve to define a natural environment for research into link formation behavior with large numbers of heterogeneous network participants. |
| Keywords: | Network formation, Social network analysis, Blogosphere, VOSON, Agentbased simulation |
| JEL: | D85 C63 L86 |
| Date: | 2007–10 |
| URL: | http://d.repec.org/n?u=RePEc:ihs:ihsesp:218&r=cmp |
| By: | Jorge M. S. Valente (LIAAD, Faculdade de Economia, Universidade do Porto, Portugal) |
| Abstract: | In this paper, we consider the single machine scheduling problem with linear earliness and quadratic tardiness costs, and no machine idle time. We present heuristic algorithms based on the beam search technique. These algorithms include classic beam search procedures, as well as the filtered and recovering variants. Several dispatching rules are considered as evaluation functions, in order to analyse the effect of different rules on the effectiveness of the beam search algorithms. The computational results show that using better rules indeed improves the performance of the beam search heuristics. The detailed, filtered and recovering beam search procedures outperform the best existing heuristic. The best results are given by the recovering and detailed variants, which provide objective function values that are quite close to the optimum. For small to medium size instances, either of these procedures can be used. For larger instances, however, the detailed beam search algorithm requires excessive computation times, and the recovering beam search procedure then becomes the heuristic of choice. |
| Keywords: | scheduling, single machine, linear earliness, quadratic tardiness, beam search, heuristics |
| Date: | 2007–10 |
| URL: | http://d.repec.org/n?u=RePEc:por:fepwps:250&r=cmp |
| By: | Tatiana Bassetto (Department of Applied Mathematics, University of Venice); Francesco Mason (Department of Applied Mathematics, University of Venice) |
| Abstract: | In the 2-period Balanced Traveling Salesman Problem (2B-TSP), the customers must be visited over a period of two days: some must be visited daily, and the others on alternate days (even or odd days); moreover, the number of customers visited in every tour must be balancedâ, i.e. it must be the same or, alternatively, the difference between the maximum and the minimum number of visited customers must be less than a given threshold. The salesman's objective is to minimize the total distance travelled over the two tours. Although this problem may be viewed as a particular case of the Period Traveling Salesman Problem, in the 2-period Balanced TSP the assumptions allow for emphasizing on routing aspects, more than on the assignment of the customers to the various days of the period. The paper proposes two heuristic algorithms particularly suited for the case of Euclidean distances between the customers. Computational experiences and a comparison between the two algorithms are also given. |
| JEL: | C61 |
| Date: | 2007 |
| URL: | http://d.repec.org/n?u=RePEc:vnm:wpaper:154&r=cmp |
| By: | ; Lietz C |
| Abstract: | The aim of this paper is to evaluate whether policy reforms in Austria between 1998 and 2005 were successful in meeting redistributive objectives and in reducing poverty. For the analysis we use the tax/benefit micro-simulation model EUROMOD. Due to the sequence of reforms and the use of two datasets, the period under review is split into two parts: 1998 to 2003 and 2003 to 2005. Important changes in the first period were the tax reform 2000, the introduction of the universal childcare benefit (“Kinderbetreuungsgeld”) as well as increases in family-targeted benefits and tax reliefs. We find that the policy reforms were in general clearly progressive and family-friendly. However, as with elderly people, the situation did not improve for all population groups at risk of poverty. In the period from 2003 to 2005 the tax reform 2004/05 was introduced and contributions to health insurance were raised. We find that the measures had no significant impact on poverty and income distribution; however, in total they increased the disposable income for almost all population groups. The analysis is completed by the assessment of the redistributive impact of two hypothetical policy changes in favour of lower income groups, namely the continuous introduction of employees’ social security contributions above the lower threshold for contributions (“Geringfügigkeitsgrenze”) and the yearly indexation of family benefits. |
| Keywords: | Austria, policy reform, inequality, redistribution, micro-simulation, |
| JEL: | C8 D31 I3 |
| Date: | 2007–05 |
| URL: | http://d.repec.org/n?u=RePEc:ese:emodwp:em3/07&r=cmp |
| By: | Luis Rivera (CLACDS-INCAE); Hugo Rojas-Romagosa (CPB (the Hague)) |
| Abstract: | Using a global CGE model, we assess the potential macro-economic effects of a future European Union - Central American Association Agreement (EU-CAAA). Currently, many agricultural products from Central America (CA) enter duty-free to the European Union (EU); with two notable exceptions: bananas and sugar. We find that liberalizing the access to both products will bring significant gains to CA, while excluding them from the negotiations will bring no static gains. If trade facilitation mechanisms are implemented and we allow for the expected increase in FDI inflows to CA, welfare gains improve for all scenarios but are conditions on the level of EU agricultural liberalization. |
| Keywords: | EU-CAAA FTA, trade policy, free trade agreement, CGE models, bananas, sugar |
| JEL: | F13 F15 C68 |
| Date: | 2007–10 |
| URL: | http://d.repec.org/n?u=RePEc:lnz:wpaper:20071001&r=cmp |
| By: | Ruud Egging; Steven A. Gabriel; Franziska Holz; Jifang Zhuang |
| Abstract: | In this paper, we present a detailed and comprehensive complementarity model for computing market equilibrium values in the European natural gas system. Market players include producers and their marketing arms which we call "transmitters", pipeline and storage operators, marketers, LNG liquefiers, regasifiers, tankers, and three end-use consumption sectors. The economic behavior of producers, transmitters, pipeline and storage operators, liquefiers and regasifiers is modeled via optimization problems whose Karush-Kuhn-Tucker (KKT) optimality conditions in combination with market-clearing conditions form the complementarity system. The LNG tankers, marketers and consumption sectors are modeled implicitly via appropriate cost functions, aggregate demand curves, and ex-post calculations, respectively. The model is run on several case studies that highlight its capabilities, including a simulation of a disruption of Russian supplies via Ukraine. |
| Keywords: | European natural gas market, global LNG market, mixed complementarity problem |
| JEL: | C61 L95 |
| Date: | 2007 |
| URL: | http://d.repec.org/n?u=RePEc:diw:diwwpp:dp732&r=cmp |
| By: | Dalila B. M. M. Fontes (LIAAD and Faculdade de Economia da Universidade do Porto, Portugal); Luís Camões (Banif -- Banco Internacional do Funchal); Fernando A. C. C. Fontes (Departamento de Matemática para a Ciência e Tecnologia, Universidade do Minho) |
| Abstract: | In this work we address investment decisions using real options. A standard numerical approach for valuing real options is dynamic programming. The basic idea is to establish a discrete-valued lattice of possible future values of the underlying stochastic variable (demand in our case). For most approaches in the literature, the stochastic variable is assumed normally distributed and then approximated by a binomial distribution, resulting in a binomial lattice. In this work, we investigate the use of a sparse Markov chain to model such variable. The Markov approach is expected to perform better since it does not assume any type of distribution for the demand variation, the probability of a variation on the demand value is dependent on the current demand value and thus, no longer constant, and it generalizes the binomial lattice since the latter can be modelled as a Markov chain. We developed a stochastic dynamic programming model that has been implemented both on binomial and Markov models. A numerical example of a production capacity choice problem has been solved and the results obtained show that the investment decisions are different and, as expected the Markov chain approach leads to a better investment policy. |
| Keywords: | Flexible Capacity Investments, Real Options, Markov Chains, Dynamic Programming |
| JEL: | C61 G31 |
| Date: | 2007–07 |
| URL: | http://d.repec.org/n?u=RePEc:por:fepwps:246&r=cmp |