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Gempack
GEMPACK (General Equilibrium Modelling PACKage) is a modeling system for CGE economic models, used at the Centre of Policy Studies (CoPS) in Melbourne, Australia, and sold to other CGE modellers. Some of the more well-known CGE models solved using GEMPACK are the GTAP model of world trade, and the MONASH, MMRF, ORANI-G and TERM models used at CoPS. All these models share a distinctive feature: they are formulated as a system of differential equations in percentage change form; however, this is not required by GEMPACK. Main features A characteristic feature of CGE models is that an initial solution for the model can be readily constructed from a table of transaction values (such as an input-output table or a social accounting matrix) that satisfies certain basic accounting restrictions. GEMPACK builds on this feature by formulating the CGE model as an initial value problem which is solved using standard techniques. The GEMPACK user specifies her model by constructing a text file ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GTAP
GTAP (the Global Trade Analysis Project) is a global network of researchers (mostly from universities, international organizations, and economic and climate/resource ministries of governments) who conduct quantitative analysis of international economic policy issues, including trade policy, climate policy, and globalization linkages to inequality and employment. The consortium produces a consistent global economic database (the GTAP Data Base) which is widely used in the research community to study prospective international economic policy around these issues. While the consortium includes a large number of international organizations, GTAP itself is coordinated by the Center for Global Trade Analysis, located at Purdue University. GTAP consortium and data base Founded by Thomas Hertel in 1992, the project grew out of the Australian IMPACT and SALTER modelling projects, and was heavily influenced by Alan Powell. It is currently directed by Dominique van der Mensbrugghe. A cent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ORANI (economic Model)
Peter Bishop Dixon AO FASSA (born 23 July 1946) is an Australian economist known for his work in general equilibrium theory and computable general equilibrium models. He has published several books and more than two hundred academic papers on economic modelling and economic policy analysis. Career Born in Melbourne to Herbert Bishop Dixon and Margaret Vera Laybourne-Smith, Dixon attended Melbourne Grammar School and Monash University (BEc, 1967), Harvard ( AM, PhD 1972) where he worked as teaching assistant from 1970 to 1972. Dixon then worked from 1972 until 1974 for the International Monetary Fund in Washington and for the Reserve Bank of Australia in Sydney in 1974/75. In 1974 he returned to Monash University. As a senior lecturer in the economics department and consultant to the Australian government's IMPACT project under Alan Powell until 1978, he started work on general equilibrium theory. Powell and Dixon were the joint recipients of the 1983 Research Medal of the Royal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RunGEM
RunGEM is a freeware component of the commercial modelling package, Gempack. It is mainly used for solving (i.e., simulating with) computable general equilibrium Computable general equilibrium (CGE) models are a class of economic models that use actual economic data to estimate how an economy might react to changes in policy, technology or other external factors. CGE models are also referred to as AGE (appl ... (CGE) models. It does not allow a user to change a model's specification or to create a new model. External links RunGEM Homepage Computer algebra systems {{science-software-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computable General Equilibrium
Computable general equilibrium (CGE) models are a class of economic models that use actual economic data to estimate how an economy might react to changes in policy, technology or other external factors. CGE models are also referred to as AGE (applied general equilibrium) models. Overview A CGE model consists of equations describing model variables and a database (usually very detailed) consistent with these model equations. The equations tend to be neoclassical in spirit, often assuming cost-minimizing behaviour by producers, average-cost pricing, and household demands based on optimizing behaviour. However, most CGE models conform only loosely to the theoretical general equilibrium paradigm. For example, they may allow for: # non-market clearing, especially for labour (unemployment) or for commodities (inventories) # imperfect competition (e.g., monopoly pricing) # demands not influenced by price (e.g., government demands) A CGE model database consists of: # tables of transacti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Model
Computer simulation is the process of mathematical modelling, performed on a computer, which is designed to predict the behaviour of, or the outcome of, a real-world or physical system. The reliability of some mathematical models can be determined by comparing their results to the real-world outcomes they aim to predict. Computer simulations have become a useful tool for the mathematical modeling of many natural systems in physics (computational physics), astrophysics, climatology, chemistry, biology and manufacturing, as well as human systems in economics, psychology, social science, health care and engineering. Simulation of a system is represented as the running of the system's model. It can be used to explore and gain new insights into new technology and to estimate the performance of systems too complex for analytical solutions. Computer simulations are realized by running computer programs that can be either small, running almost instantly on small devices, or large-sca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richardson Extrapolation
In numerical analysis, Richardson extrapolation is a sequence acceleration method used to improve the rate of convergence of a sequence of estimates of some value A^\ast = \lim_ A(h). In essence, given the value of A(h) for several values of h, we can estimate A^\ast by extrapolating the estimates to h=0. It is named after Lewis Fry Richardson, who introduced the technique in the early 20th century, though the idea was already known to Christiaan Huygens in his calculation of π. In the words of Birkhoff and Rota, "its usefulness for practical computations can hardly be overestimated."Page 126 of Practical applications of Richardson extrapolation include Romberg integration, which applies Richardson extrapolation to the trapezoid rule, and the Bulirsch–Stoer algorithm for solving ordinary differential equations. Example of Richardson extrapolation Suppose that we wish to approximate A^*, and we have a method A(h) that depends on a small parameter h in such a way that A( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graphical User Interface
The GUI ( "UI" by itself is still usually pronounced . or ), graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, instead of text-based UIs, typed command labels or text navigation. GUIs were introduced in reaction to the perceived steep learning curve of CLIs ( command-line interfaces), which require commands to be typed on a computer keyboard. The actions in a GUI are usually performed through direct manipulation of the graphical elements. Beyond computers, GUIs are used in many handheld mobile devices such as MP3 players, portable media players, gaming devices, smartphones and smaller household, office and industrial controls. The term ''GUI'' tends not to be applied to other lower-display resolution types of interfaces, such as video games (where HUD (''head-up display'') is preferred), or not including flat screens like volumetric displays because ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear Complementarity Problem
In mathematical optimization theory, the linear complementarity problem (LCP) arises frequently in computational mechanics and encompasses the well-known quadratic programming as a special case. It was proposed by Cottle and Dantzig in 1968. Formulation Given a real matrix ''M'' and vector ''q'', the linear complementarity problem LCP(''q'', ''M'') seeks vectors ''z'' and ''w'' which satisfy the following constraints: * w, z \geqslant 0, (that is, each component of these two vectors is non-negative) * z^Tw = 0 or equivalently \sum\nolimits_i w_i z_i = 0. This is the complementarity condition, since it implies that, for all i, at most one of w_i and z_i can be positive. * w = Mz + q A sufficient condition for existence and uniqueness of a solution to this problem is that ''M'' be symmetric positive-definite. If ''M'' is such that has a solution for every ''q'', then ''M'' is a Q-matrix. If ''M'' is such that have a unique solution for every ''q'', then ''M'' is a P-matrix ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Policy Modeling
The ''Journal of Policy Modeling'' is a peer-reviewed academic journal that covers research in economics and policy. The journal was established in 1979 and is published by Elsevier for the Society for Policy Modeling. It publishes academic research papers analyzing national and international policy issues. The Journal of Policy Modeling is ranked by the CNRS, the ESSEC Business School, and SCIMago, among others. According to the ''Journal Citation Reports'', the journal has a 2018 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... of 1.2. References External links * Elsevier academic journals Economics journals Publications established in 1979 English-language journals {{econ-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gaussian Quadrature
In numerical analysis, a quadrature rule is an approximation of the definite integral of a function, usually stated as a weighted sum of function values at specified points within the domain of integration. (See numerical integration for more on quadrature rules.) An -point Gaussian quadrature rule, named after Carl Friedrich Gauss, is a quadrature rule constructed to yield an exact result for polynomials of degree or less by a suitable choice of the nodes and weights for . The modern formulation using orthogonal polynomials was developed by Carl Gustav Jacobi in 1826. The most common domain of integration for such a rule is taken as , so the rule is stated as :\int_^1 f(x)\,dx \approx \sum_^n w_i f(x_i), which is exact for polynomials of degree or less. This exact rule is known as the Gauss-Legendre quadrature rule. The quadrature rule will only be an accurate approximation to the integral above if is well-approximated by a polynomial of degree or less on . The Gaus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Midpoint Method
In numerical analysis, a branch of applied mathematics, the midpoint method is a one-step method for numerically solving the differential equation, : y'(t) = f(t, y(t)), \quad y(t_0) = y_0 . The explicit midpoint method is given by the formula the implicit midpoint method by for n=0, 1, 2, \dots Here, h is the ''step size'' — a small positive number, t_n=t_0 + n h, and y_n is the computed approximate value of y(t_n). The explicit midpoint method is sometimes also known as the modified Euler method, the implicit method is the most simple collocation method, and, applied to Hamiltonian dynamics, a symplectic integrator. Note that the modified Euler method can refer to Heun's method, for further clarity see List of Runge–Kutta methods. The name of the method comes from the fact that in the formula above, the function f giving the slope of the solution is evaluated at t = t_n + h/2= \tfrac, the midpoint between t_n at which the value of y(t) is known and t_ at which the va ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
