Search results for " Mathematical methods"
showing 9 items of 19 documents
Note about the concept of ‘Net Multipliers'
2002
International audience; Net multipliers, as introduced by Oosterhaven and Stelder (2002) accept outputs as entries instead of final demand. They are found by multiplying ordinary multipliers by the final demand ratio over the sector's output. This pragmatic solution suffers from ratio instability over time. The alternative net multipliers proposed here are based on the interpretation of the Leontief inverse matrix for the effects generated at each round. The new solution is not sensitive to the size of impacts. Now net multiplier is equal to the corresponding ordinary multiplier minus one, and the ordering of multipliers is unchanged.
On Boolean topological methods of structural analysis
2001
The properties of Boolean methods of structural analysis are used to analyze the intern structure of linear or non linear models. Here they are studied on the particular example of qualitative methods of input-output analysis. First, it is shown that these methods generate informational problems like biases when working in money terms instead of percentages, losses of information, increasing of computation time, and so on. Second, considering three ways to do structural analysis, analysis from the inverse matrix, from the direct matrix and from layers (intermediate flow matrices), these methods induce topological problems; the adjacency of the adjacency cannot be defined from the inverse ma…
Biproportion et offre dominante (A propos de l'article d'André Torre ‘Sur la signification théorique du modèle d'offre multisectoriel')
1996
One replies here to partisans of the reject of the supply-driven model in input-output analysis and especially to A. Torre (Revue Economique, 5, 44, 951-970). First of all, demand-driven hypothesis (Leontief) and supply-driven hypothesis (Ghosh) are symmetrical and incompatible, what forbidden to reject the second to the motive that it depends on the first. Secondly, the results earlier obtained for France of 1970 to 1985 from the method of the biproportionnal filter show that there is so much instability in the long term in the columns than in the rows of the flow matrix. Thirdly, the assimilation of the usage of allocation coefficients to the adoption of the supply-side model is excessive.
A Note on Qualitative Input-Output Analysis
1995
International audience; The paper discusses qualitative input—output methods. It is shown that information is lost. Because the binaiy relationship constructed by qualitative methods is not transitive, the model lacks economic consistency. Qualitative methods are tending to become more sophisticated, but some problems of economic interpretation are raised.
Normalizing biproportional methods
2002
International audience; Biproportional methods are used to update matrices: the projection of a matrix Z to give it the column and row sums of another matrix is R Z S, where R and S are diagonal and secure the constraints of the problem (R and S have no signification at all because they are not identified). However, normalizing R or S generates important mathematical difficulties: it amounts to put constraints on Lagrange multipliers, non negativity (and so the existence of the solution) is not guaranteed at equilibrium or along the path to equilibrium.
Is the Ghosh model interesting?
2009
International audience; The overall value of the Ghosh model is appraised. Its treatment of quantities and prices is scrutinized by examining the variant with data in quantities and prices, and the variant with data in value and price indexes. The methodology involves returning to the accounting equations and shows that: (i) the Ghosh model offers solutions of limited interest, being incapable of providing prices or price indexes separately from quantities; (ii) what is taken to be the equation of Ghosh's value model is actually that of Ghosh's physical model; (iii) the Ghosh model may serve for cost-push exercises, but the dual of the Leontief model performs the same task in a much simpler…
Biproportional methods of structural change analysis: A typological survey
2004
International audience; Analysts often are interested in learning how much an exchange system has changed over time or how two different exchange systems differ. Identifying structural difference in exchange matrices can be performed using either 'directed' or 'undirected' methods. Directed methods are based on the computation and comparison of column- or row-normalizations of the matrices. The choice of row or column for the normalization implies a specific direction of the exchanges, so that the column-wise normalized results should not be compared to the row-wise normalized results. In this category fall the simple comparison of coefficient matrices and the causative method. Undirected m…
Biproportional Method for Analysing Interindustry Dynamics: the case of France
1990
Two elements are being presented in this paper: (1) A new and original method for analysing matrix dynamics, called the synthetical biproportional projector method (SBP), which can be used to project input–output tables and compare one with another. (2) Some results for France for the important period 1970–85. The paper starts with the observation that no systematic study of the change in the French productive structure as displayed In the input–output tables (tableaux entries-sorties in France) has ever been made. This is unfortunate, since a complete series of data is now available concerning a key period of the French economic evolution including the petroleum crisis, European integratio…
OpenMolcas: From Source Code to Insight
2019
In this article we describe the OpenMolcas environment and invite the computational chemistry community to collaborate. The open-source project already includes a large number of new developments realized during the transition from the commercial MOLCAS product to the open-source platform. The paper initially describes the technical details of the new software development platform. This is followed by brief presentations of many new methods, implementations, and features of the OpenMolcas program suite. These developments include novel wave function methods such as stochastic complete active space self-consistent field, density matrix renormalization group (DMRG) methods, and hybrid multico…