Search results for "jel:C63"
showing 9 items of 9 documents
Bicausative matrices to measure structural change: Are they a good tool?
1999
The causative-matrix method to analyze temporal change assumes that a matrix transforms one Markovian transition matrix into another by a left multiplication of the first matrix; the method is demand-driven when applied to input-output economics. An extension is presented without assuming the demand-driven or supply-driven hypothesis. Starting from two flow matrices X and Y, two diagonal matrices are searched, one premultiplying and the second postmultiplying X, to obtain a result the closer as possible to Y by least squares. The paper proves that the method is deceptive because the diagonal matrices are unidentified and the interpretation of results is unclear. Keywords : Input-Output ; Ch…
About the criteria of output coincidence for forecasts to determine the orientation of the economy (application for France, 1980-1997)
2000
This note indicates that the method of output coincidence for forecasts used to determine if sectors are demand-driven or supply-driven in an input-output framework mixes two effects, the structural effect (choosing between demand and supply driven models) and the effect of an exogenous factor (final demand or added-value). The note recalls that another method is possible, the comparison of the stability of technical and allocation coefficients, generalized by the biproportional filter: if for a sector, after biproportional filtering, column coefficients are more stable than row coefficients, then this sector is declared as not supply-driven (but one cannot decide that it is demand-driven a…
Analyzing structural change : the biproportional mean filter and the biproportional bimarkovian filter
1998
The biproportional filter was created to analyze structural change between two input-output matrices by removing the effect of differential growth of sectors without predetermining if the model is demand or supply-driven, but with the disadvantage that projecting a first matrix on a second is not the same thing than projecting the second matrix on the first. Here two alternative methods are proposed which has not this last drawback, with the additional advantage for the biproportional bimarkovian filter that effects of sector size are also removed. Methods are compared with an application for France for 1980 and 1996.
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.
A Unified Approach to Portfolio Optimization with Linear Transaction Costs
2004
In this paper we study the continuous time optimal portfolio selection problem for an investor with a finite horizon who maximizes expected utility of terminal wealth and faces transaction costs in the capital market. It is well known that, depending on a particular structure of transaction costs, such a problem is formulated and solved within either stochastic singular control or stochastic impulse control framework. In this paper we propose a unified framework, which generalizes the contemporary approaches and is capable to deal with any problem where transaction costs are a linear/piecewise-linear function of the volume of trade. We also discuss some methods for solving numerically the p…
Failure of the normalization of the RAS method : absorption and fabrication effects are still incorrect
2000
The r and s vectors of the RAS method of updating matrices are presented often as corresponding to an absorption effect and a fabrication effect. Here, it is proved that these vectors are not identified, so their interpretation in terms of fabrication and absorption effect is incorrect and even if a normalization was proposed to remove underidentification, this normalization fails and poses many difficulties.. Keywords : Input-Output ; RAS ; Biproportion
APPLYING PERT AND CRITICAL PATH METHOD IN HUMAN RESOURCE TRAINING
2011
The subject of the article is referring to the modelling and simulating of the formation of human resources by applying the PERT/CPM (Program Evaluation and Review Technique/Critical Path Method) and the taking into consideration of some risks associated to this activity. The aim of the article is to offer practical support to the management of organizations in order to make a formation program of human resources, which implies activities of precedence and interrelated, critical paths, the distribution of time resources and necessary costs for the fulfilment of the organizational objectives.
The impact of classes of innovators on Technology, Financial Fragility and Economic Growth
2011
In this paper, we study innovation processes and technological change in an agent-based model. By including a behavioral switching among heterogeneous innovative firms, which can endogenously change among three different classes (single innovators, collaborative innovators and imitators) on the base of their R&D expenditures, the model is able to replicate, via simulations, well known industrial dynamic and growth type stylized facts. Moreover, we focus the analysis on the impact of these three innovation categories on micro, meso and macro aggregates. We find that collaborative companies are those having the highest positive impact on the economic system. The model is then used to study th…
Interpretation of the RAS method : absorption and fabrication effects are incorrect.
1999
The r and s vectors of the RAS method of updating matrices are presented often as corresponding to an absorption effect and a fabrication effect. Here, it is proved that these vectors are unidentified, so their interpretation in terms of fabrication and absorption effect is incorrect..