Modelling a Disintegrating Economy by Markov Processes

V.A. Dikarev, A.E. Veprik, and V.I. Zabelin
Kharkov Technical University of Radioelectronics, Ukraine

Abstract

Possibility of control of single economic structure disintegration to not connected or weakly connected economies, when the main parameters of them are equal to any pre-assigned values at the moments, near or equal to the moment of disintegration is investigated in this report. Disintegration of economies is studied by means of finite non-homogeneous Markov processes with continious time. Disinegration is assumed to occur during finite time interval tex2html_wrap_inline20 . The analysis is made by Kolmogorov equations with infinitesimal matrix tex2html_wrap_inline22 . The state j, (j=1,...,n) of studied process tex2html_wrap_inline28 is assumed to be one of the possible states of investigated economy. It can be described by main economic indices. Elements of matric tex2html_wrap_inline22 describe interaction economic indices dynamics.

Let tex2html_wrap_inline32 and tex2html_wrap_inline34 be diagonal blocks of matrix tex2html_wrap_inline22 . They correspond to disintegrating economy. Two cases are considered: when elements of tex2html_wrap_inline22 not belonging to tex2html_wrap_inline32 and tex2html_wrap_inline34 tend to zero when tex2html_wrap_inline44 or are small in the vicinity of tex2html_wrap_inline46 . These are cases of complete break and reduction of economical contacts. Components tex2html_wrap_inline48 of vector p(s) are probabilities of process tex2html_wrap_inline52 being in state j at moment s. Let some set of values tex2html_wrap_inline58 , j=1,...,n, tex2html_wrap_inline62 , tex2html_wrap_inline64 , determines state probabilities of tex2html_wrap_inline28 (state of disinegrating economy) at the moment of stabilization. It means, that tex2html_wrap_inline48 tend to tex2html_wrap_inline58 when s tend to tex2html_wrap_inline74 , tex2html_wrap_inline76 , j=1,...,n or tex2html_wrap_inline80 when s is enough close to tex2html_wrap_inline74 and tex2html_wrap_inline86 is small. Let both conditions be accomplished provided by any initial distribution at tex2html_wrap_inline88 . In mentioned cases moment tex2html_wrap_inline74 will be named as a point of strict stabilization or point of rough stabilization ( tex2html_wrap_inline92 -stabilization). Cases tex2html_wrap_inline94 , tex2html_wrap_inline96 , tex2html_wrap_inline98 for strict and rough stabilizations are investigated. In all cases matrices tex2html_wrap_inline32 and tex2html_wrap_inline34 were determined to provide stabilization at moment tex2html_wrap_inline74 :

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Realization of stabilization processes in economy causes great expenses. Matrix tex2html_wrap_inline22 , stabilizing the process at moment tex2html_wrap_inline74 , can de determined not in unique way. Expenses for stabilization can be estimated by functional, describing expenses for building of matrix tex2html_wrap_inline22 . Expenses for tex2html_wrap_inline92 tend to zero. The strict stabilization is impossible if expenses are limited with the exception of some special cases.

Then the problem of rough stabilization on finite time interval [a,b] is investigated. Let tex2html_wrap_inline116 , tex2html_wrap_inline118 , tex2html_wrap_inline120 be continuous functions defined on [a,b]. It was determined, that there is continuous on [a,b] matrix tex2html_wrap_inline126 , which describe the process tex2html_wrap_inline28 state probabilities of which satisfay to the following conditions:

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Computer models of non-homogeneous Markov process were designed on base of Kolmogorov equations. These models were created for systems with numbers of states from 2 till 300. Some computer modelling experiments were carried out. We have found, that under certain conditions the process of stabilization or rough stabilization was taking place at certain moments. Also it was confirmed, that the nature of splitting of these processes depends on sort of decomposition of their infinitesimal matrices to non-interacting or almost non-interacting blocks. Computer modelling experiments on rough stabilization for finite time interval were also carried out.


Society of Computational Economics
Second International Conference on Computing in Economics and Finance
Geneva, Switzerland, 26-28 June 1996