New Economics Papers
on Computational Economics
Issue of 2008‒04‒12
seven papers chosen by

  1. KLUM@GTAP: Spatially-Explicit, Biophysical Land Use in a Computable General Equilibrium Model By Ronneberger, Kerstin; Berrittella, Maria; Boselle, Francesco; Tol, Richard
  2. Are CGE Models Still Useful in Economic Policy Making? By Renato Galvão Flôres Junior
  3. Would a Flat Tax Stimulate Entrepreneurship in Germany? : A Behavioural Microsimulation Analysis Allowing for Risk By Frank M. Fossen
  4. Economic perspectives for Central America after CAFTA By Joseph F. Francois; Luis Rivera; Hugo Rojas-Romagosa
  5. The Pyramidal Capacitated Vehicle Routing Problem By Lysgaard, Jens
  6. Physical and Financial Virtual Power Plants By Bert Willems
  7. Bibliometric Mapping of the Computational Intelligence Field By Eck, N.J.P. van; Waltman, L.

  1. By: Ronneberger, Kerstin; Berrittella, Maria; Boselle, Francesco; Tol, Richard
    Abstract: *Chapter 12 of the forthcoming book "Economic Analysis of Land Use in Global Climate Change Policy," edited by Thomas W. Hertel, Steven Rose, and Richard S.J. Tol. In this paper the global agricultural land use model KLUM is coupled to an extended version of the computable general equilibrium model (CGE) GTAP in order to consistently assess the integrated impacts of climate change on global cropland allocation and its implications for economic development. The methodology is innovative as it introduces dynamic economic land-use decisions based also on the biophysical aspects of land into a state-of the-art CGE; it further allows the projection of resulting changes in cropland patterns at a spatially explicit level. A convergence test and illustrative future simulations underpin the robustness analysis and serve to highlight the potential of the coupled system. Reference simulations with the uncoupled models emphasize the impact and relevance of the coupling; the results of coupled and uncoupled simulations can differ by several hundred percent.
    Date: 2008
  2. By: Renato Galvão Flôres Junior (EPGE/FGV)
    Date: 2008–02
  3. By: Frank M. Fossen
    Abstract: When possible income tax reforms are debated, the suspected impact on entrepreneurship is often used as an argument in favour or against a certain policy. Quantitative ex-ante evaluations of the effect of certain tax reform options on entrepreneurship based on microeconometric research have not been provided by the literature, however. This paper estimates the ex-ante effects of the German tax reform 2000 and of two hypothetical flat tax scenarios on entries into and exits out of self-employment in Germany. For the estimation I apply a microsimulation model which is based on the tax-benefit model STSM and on structural microeconometric models of transitions into and out of self-employment. These structural models include an estimated parameter of risk aversion. The simulation results indicate that flatter tax systems do not encourage, but rather discourage people from choosing self-employment. This is explained by the reduction of entrepreneurs' income risk through progressive taxation.
    Keywords: Entrepreneurship, income taxation, risk, tax reform 2000, flat tax
    JEL: H24 J23 L26 D81
    Date: 2008
  4. By: Joseph F. Francois; Luis Rivera; Hugo Rojas-Romagosa
    Abstract: Using a GTAP CGE application, we assess the main economic results of CAFTA for Central America (CA). Currently, Central America enjoys preferential access to the US market through the Caribbean Basin Initiative (CBI). CAFTA will consolidate and augment these concessions. Meanwhile, the agreement requires widespread opening of CA markets to US imports over time. The implementation of the ATC protocol in 2005 implies increased Chinese competition for the region in the textile and apparel sectors. CAFTA will balance for this new source of competition by allowing better access for CA textiles and apparel products, while creating large opportunities for labour market improvements and FDI inflows to Central America. If these opportunities are exploited, the region has much to gain from CAFTA. However, we also find a strong sectoral readjustment from agricultural sectors to maquila-based industries, which could create important adjustment strains.
    Keywords: Free trade agreements; CGE models; GTAP applications
    JEL: F13 C68
    Date: 2008–02
  5. By: Lysgaard, Jens (Department of Business Studies, Aarhus School of Business)
    Abstract: This paper introduces the Pyramidal Capacitated Vehicle Routing Problem (PCVRP) as a restricted version of the Capacitated Vehicle Routing Problem (CVRP). In the PCVRP each route is required to be pyramidal in a sense generalized from the Pyramidal Traveling Salesman Problem (PTSP). A pyramidal route is de ned as a route on which the vehicle rst visits customers in increasing order of customer index, and on the remaining part of the route visits customers in decreasing order of customer index. Provided that customers are indexed in nondecreasing order of distance from the depot, the shape of a pyramidal route is such that its traversal can be divided in two parts, where on the rst part of the route, customers are visited in nondecreasing distance from the depot, and on the remaining part of the route, customers are visited in nonincreasing distance from the depot. Such a route shape is indeed found in many optimal solutions to CVRP instances. An optimal solution to the PCVRP may therefore be useful in itself as a heuristic solution to the CVRP. Further, an attempt can be made to nd an even better CVRP solution by solving a TSP, possibly leading to a non-pyramidal route, for each of the routes in the PCVRP solution. This paper develops an exact branch-and-cut-and-price (BCP) algorithm for the PCVRP. At the pricing stage, elementary routes can be computed in pseudo-polynomial time in the PCVRP, unlike in the CVRP. We have therefore implemented pricing algorithms that generate only elementary routes. Computational results suggest that PCVRP solutions are highly useful for obtaining near-optimal solutions to the CVRP. Moreover, pricing of pyramidal routes may due to its eciency prove to be very useful in column generation for the CVRP.
    Keywords: vehicle routing; pyramidal traveling salesman; branch-and-cut-and-price
    Date: 2008–03–25
  6. By: Bert Willems
    Abstract: Regulators in Belgium and the Netherlands use different mechanisms to mitigate generation market power. In Belgium, antitrust authorities oblige the incumbent to sell financial Virtual Power Plants, while in the Netherlands regulators have been discussing the use of physical Virtual Power Plants. This paper uses a numerical game theoretic model to stimulate the behaviour of the generation firms and to compare the effects of both systems on the market power of the generators. It shows that financial Virtual Power Plants are better for society.
    Date: 2008–03
  7. By: Eck, N.J.P. van; Waltman, L. (Erasmus Research Institute of Management (ERIM), RSM Erasmus University)
    Abstract: In this paper, a bibliometric study of the computational intelligence field is presented. Bibliometric maps showing the associations between the main concepts in the field are provided for the periods 1996–2000 and 2001–2005. Both the current structure of the field and the evolution of the field over the last decade are analyzed. In addition, a number of emerging areas in the field are identified. It turns out that computational intelligence can best be seen as a field that is structured around four important types of problems, namely control problems, classification problems, regression problems, and optimization problems. Within the computational intelligence field, the neural networks and fuzzy systems subfields are fairly intertwined, whereas the evolutionary computation subfield has a relatively independent position.
    Keywords: bibliometrics;bibliometric mapping;computational intelligence;neural networks;fuzzy systems;evolutionary computation
    Date: 2008–03–25

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