Parametrical Regulation of Economic Growth Based on the Stochastic Computable Model of General Equilibrium with Knowledge Sector Abdykappar A. Ashimov, Bahyt T. Sultanov, Zheksenbek M. Adilov, Yuriy V. Borovskiy, Dauren K. Suissenbayev, Askar A. Ashimov Parametrical regulation Kazakh National Technical University Almaty, Kazakhstan ashimov37@mail.ru, yuborovskiy@gmail.com Abstract — The paper aims to present one new method of parametrical identification, the results of development of the parametrical regulation theory and to show the application efficiency of the proposed method of identification and theoretical results for solving the respective problems of application. The paper describes the proposed method of parametrical identification, we formulated and proved the theorems about the conditions for the existence of one of the problems of variational calculus on the synthesis of the optimal law of parametrical regulation and about the conditions for continuous dependence of optimal values of the criterion of the given problem on unregulated parameters applying the mathematical objects of a discrete stochastic control system. The problems of parametrical identification of the calculated general equilibrium model with knowledge sector were solved effectively. Also we show the efficiency of determining the optimal values (in sense of the criterion, that characterizes economic growth) of the parameters of deterministic and stochastic versions of the computable general equilibrium model with knowledge sector. dynamic equations of a corresponding mathematical model of economic system. Keywords — stochastic control, modelling and simulation, identification and estimation, theory of parametrical regulation - the theorem about sufficient conditions of continuous dependence of a criterion’s optimal values of a problem of variational calculus on synthesis of regulation optimal laws on values of uncontrolled parameters. I. INTRODUCTION As it is known [7], presented in the literature models of national economy reflect in the mathematical form important properties of economic system and do not account for a set of appearing shocking effects, for example as irregularities from the aspect of supply (productivity and supply of labor), irregularities on the demand side (preferences, investment specificity, government spending), effect of increasing costs or margins (markups, salary supplements, risk premium) and others. According to the theory of business cycles, factors that define economic growth and business cycles are factors of the same nature [8]. Therefore the study of economic growth against the background of business cycles should be conducted on the basis of one mathematical model. In the present work the study of economic growth against the background of business cycles the following assumption was made: mentioned above and other possible irregularities in a deterministic mathematical model of national economy can be approximated by adding additive noise to the right sides of In this paper the theory of parametrical regulation of national economy evolution (efficiency of which was shown on the class of models as a continuous or discrete dynamic systems [1], [2], [3], [4]) develops to the class of discrete dynamic systems with additive noise, the important subclass of which are computable models of general equilibrium (so called CGE-models [5]) with additive noise. In particular, in the framework of development of the parametrical regulation theory in this paper for discrete dynamical systems with additive noise theorems about sufficient conditions were formulated and proved: - the theorem about sufficient conditions of a solution existence to the problem of variational calculus on a choice of the system parameters’ optimal values in the given set of their values (on synthesis of optimal laws of regulation). Fulfillment of the conditions of solution existence of the stated problem of variational calculus guarantees, in particular, finiteness of the expectation of the phase trajectories process on a finite time interval. In this paper the discrete stochastic model, obtained from deterministic computable model of general equilibrium of economic sectors of Makarov [5] by adding additive noise to the right sides of the model’s dynamical equations, was considered as an example of theoretical results applications. The problem of parametrical identification of the researched model was solved based on statistical data on economy evolution of the Republic of Kazakhstan. The problem of optimal (in sense of some criterion) economic growth of national economy of the Republic of Kazakhstan was formulated and solved applying methods of the parametrical regulation theory based on deterministic and stochastic variants of a computable model of general equilibrium with knowledge sector. II. ELEMENTS OF THE PARAMETRICAL REGULATION THEORY BASED ON THE DISCRETE DYNAMIC SYSTEM WITH ADDITIVE NOISE We consider discrete stochastic regulated system ๐ฅ(๐ก + 1) = ๐(๐ฅ(๐ก), ๐ข(๐ก), ๐) + ξ(๐ก), ๐ก = 0, … , ๐ − 1,๏ ๏ ๏จ๏ฑ๏ฉ๏ ๏ ๐ฅ(0) = ๐ฅ0 ๏ฎ๏ ๏จ๏ฒ๏ฉ๏ Here ๐ก – time, taking nonnegative integer values; ๐ฅ = ๐ฅ(๐ก) ⊂ ๐ ๐ – function of the system (1), random vector-function of discrete argument (a vector random process); ๐ข = ๐ข(๐ก) ⊂ ๐ ๐ – regulation, vector-function of discrete argument; ๐ – deterministic vector of uncontrollable parameters, ๐ ∈ ๐ด; ๐ด – given set, ๐ด ⊂ ๐ ๐ ; ξ = ξ(๐ก) = (ξ1 (๐ก), … , ξ๐ (๐ก)) – known vector random process, which expresses the noise (as such may be, for example, an additive Gaussian white noise); ๐ – a known vector-function of its arguments; ๐ฅ0 – initial state of the system, a deterministic vector. We define the optimality criterion to be the maximization for ๐ fixed: ๐พ๐ = ๐{∑๐๐ก=1 ๐น๐ก [๐ฅ(๐ก)]}๏ฎ๏ ๏จ๏ณ๏ฉ๏ Here ๐น๐ก – are known functions; ๐ – mathematical expectation, ๐ฅ(๐ก) – a solution to the system (1), (2) for a given ๐. We introduce the phase constraints for the system (1), (2): ๐[๐ฅ(๐ก)] ∈ ๐(๐ก), ๐ก = 1, … , ๐๏ป๏ ๏จ๏ด๏ฉ๏ where ๐(๐ก) – given set. Hereinafter the mathematical expectation of a vector chance quantity means the vector of mathematical expectations of the origin of this value. where ๐ฅ(๐ก) is the solution to the system (1), (2) corresponding to the regulation ๐ข(๐ก) and set ๐ parameter value. Then the Problem 1 is reduced to maximizing the functional ๐พ = ๐พ๐ (๐ข) which is defined by the formula (3), on the set ๐๐ of allowable regulations of the system. We call the Problem 1 non-trivial, if the set ๐๐ is non-empty and contains some open set. The theorem on sufficient conditions for existence of solution to the Problem 1 (set in accordance with the method of parametrical regulation) and the theorem of continuous dependence of the optimal value of ๐พ๐ criterion of the Problem 1 on the parameter ๐ are presented below. Theorem 1. Suppose given fixed ๐ ∈ ๐ด in non-trivial Problem 1 for any ๐ก = 1, … , ๐ chance quantity ξ(๐ก) are absolutely continuous and have zero mathematical expectations, functions ๐ and ๐น๐ก satisfy the Lipschitz condition. Functions ๐ (for ๐ข ∈ ๐๐ ) and ๐น๐ก by module are constrained by some linear functions of |๐ฅ ๐ | variables (๐ฅ ๐ – coordinate of x vector). Then the Problem 1 has a solution. Theorem 2. Suppose when ๐ ∈ ๐ด and ๐ก = 1, … , ๐ for nontrivial Problem 1 chance quantity ξ(๐ก) are absolutely continuous and have zero mathematical expectations, functions ๐ and ๐น๐ก satisfy the Lipschitz condition. Functions ๐ and ๐น๐ก do not exceed a linear function with respect to |๐ฅ ๐ | function in some neighborhood of a point ๐ . Then the mapping ๐ → max ๐พ๐ (๐ข) is continuous in ๐ด. ๐ข∈๐๐ Proofs of Theorems 1 and 2 are presented in Appendix. III. REPRESENTATION OF COMPUTABLE GENERAL EQUILIBRIUM MODELS IN THE FORM OF DISCRETE STOCHASTIC DYNAMIC SYSTEMS AND THE PROBLEM OF PARAMETRICAL REGULATION OF THE NATIONAL ECONOMY EVOLUTION ON THE BASIS OF COMPUTABLE MODELS In the below considered tasks, explicit constraints on regulation are assumed: Deterministic computable general equilibrium model in general form is represented by the following system of relations [5, Ch. 3]. ๏จ๏ต๏ฉ๏ 1) The subsystem of difference equations, binding the values of endogenous variables for two consecutive years: where ๐(๐ก) – given set, ๐(๐ก) ⊂ ๐ ๐ . Sets ๐(๐ก) and ๐(๐ก) for all determined above ๐ก values are the closures of limited open sets. ๐ฅ(๐ก + 1) = ๐(๐ฅ(๐ก), ๐ฆ(๐ก), ๐ง(๐ก), ๐ข(๐ก), ๐), ๐ฅ(0) = ๐ฅ0 ๏ฎ๏ ๏จ๏ถ๏ฉ๏ ๐ข(๐ก) ∈ ๐(๐ก), ๐ก = 0, … , ๐ − 1๏ป๏ The method of parametrical regulation is used in the formulation and solution of the following variational problem, so called the problem of variational calculus of the synthesis of the optimum law of parametrical regulation. Problem 1. Given the vector of unregulated parameters ๐ ∈ ๐ด find such regulation ๐ข, that satisfies the condition (5), so that corresponding to it the solution of dynamical system (1), (2) satisfies the condition (4) and provides the maximum of the functional (3). For the fixed ๐ ∈ ๐ด let us define the set of allowable regulations for the system (1), (2) in the following manner: ๐๐ = {๐ข|๐ข(๐ก) ∈ ๐(๐ก), ๐ก = 0, … , (๐ − 1); ๐[๐ฅ(๐ก)] ∈ ๐(๐ก), ๐ก = 1, … , ๐} Here ๐ก – year number, discrete time, ๐ก = 0, … , ๐ − 1; ๐ฅฬ(๐ก) = (๐ฅ(๐ก), ๐ฆ(๐ก), ๐ง(๐ก)) ∈ ๐ ๐ – vector of the system’s endogenous variables; ๐ฅ(๐ก) ∈ ๐1 (๐ก) ⊂ ๐ ๐1 ; ๐ฆ(๐ก) ∈ ๐2 (๐ก) ⊂ ๐ ๐2 ; ๐ง(๐ก) ∈ ๐3 (๐ก) ⊂ ๐ ๐3 ๏ฎ๏ ๏จ๏ท๏ฉ๏ ๐ฅ(๐ก) variables include values of fixed assets of producing sectors, balances in agents’ bank accounts, etc.; ๐ฆ(๐ก) include agents’ demand and supply values in different markets, etc.; ๐ง(๐ก) – different values of market prices and budget shares in the markets with state prices for different economic agents; ๐ข(๐ก) and ๐ are vectors of exogenous parameters, ๐ข(t) ∈ ๐(๐ก) ⊂ ๐ ๐ – vector of controlled (regulated) parameters; ๐1 (๐ก), ๐2 (๐ก), ๐3 (๐ก), ๐(๐ก) – compact sets with nonempty interior; ๐1 + ๐2 + ๐3 = ๐ ; ๐ ∈ ๐ด ⊂ ๐ ๐ – vector of uncontrolled parameters; ๐ด – open connected set; ๐: ๐1 (๐ก) × ๐2 (๐ก) × ๐3 (๐ก) × ๐(๐ก) × ๐ด → ๐ ๐1 – continuous mapping for ๐ก = 0, … , ๐. 2) The subsystem of algebraic equations, describing behavior and interaction of agents in different markets during the selected year, these equations allow the expression of variables ๐ฆ(๐ก) in terms of exogenous parameters and the remaining endogenous variables: ๏จ๏ธ๏ฉ๏ ๐ฆ(๐ก) = ๐(๐ฅ(๐ก), ๐ง(๐ก), ๐ข(๐ก), ๐).๏ Here ๐: ๐1 (๐ก) × ๐3 (๐ก) × ๐(๐ก) × ๐ด → ๐ ๐2 mapping; ๐ก = 0, … , ๐. – continuous 3) The subsystem of recurrent relations for iterative calculations of equilibrium values of market prices in different markets and of budget shares in markets with state prices for the different economic agents: ๐ง(๐ก)[๐ + 1] = โ(๐ฆ(๐ก)[๐], ๐ง(๐ก)[๐], ๐ฟ, ๐ข(๐ก), ๐).๏ ๏จ๏น๏ฉ๏ Here ๐ = 0, 1, 2, … – iteration number; ๐ฟ – set of positive numbers (adjustable iteration constants; when their values decrease the economic system reaches the equilibrium state faster, but the risk that the price go to the negative domain increases); โ: ๐2 (๐ก) × ๐3 (๐ก) × (0, +∞)๐3 × ๐(๐ก) × ๐ด → ๐3 ๐ – continuous mapping (which is contracting when ๐ฅ(๐ก) ∈ ๐1 (๐ก), ๐ข(t) ∈ ๐(๐ก), ๐ ∈ ๐ด, are fixed and some fixed ๐ฟ. In this case โ mapping has a single fixed point, to which the iterative process (8), (9) converges); ๐ก = 0, … , ๐. Computable model (6), (8), (9) given fixed values of exogenous variables for each moment of ๐ก time defines values of endogenous variables ๐ฅฬ(๐ก) that correspond to the demand and supply equilibrium in the markets of agents’ goods and services in the framework of the algorithm below. 1) On the first step it is assumed that ๐ก = 0 and the initial values of ๐ฅ0 variables are set. 2) On the second step the initial values of ๐ง(๐ก)[0] variables are set for the current ๐ก in different markets and for different agents; with the help of (8) the values of ๐ฆ(๐ก)[0] = ๐(๐ฅ(๐ก), ๐ง(๐ก)[0], ๐ข(๐ก), ๐) are calculated (initial values of demand and supply of agents in markets of goods and services). 3) On the third step the iteration process (9) is run for current ๐ก. Meanwhile current values of demand and supply for every ๐ are found from (8): ๐ฆ(๐ก)[๐] = ๐(๐ฅ(๐ก), ๐ง(๐ก)[๐], ๐ข(๐ก), ๐) through the refinement of market prices and budget shares of economic agents. The condition for completion of iteration process is the equality of demand and supply values in different markets. As a result equilibrium values of market prices are determined in every market and budget shares in markets with government prices for different economic agents. ๐ index is omitted for such equilibrium values of endogenous variables. 4) On the next step values of ๐ฅ(๐ก + 1) variables for the next moment of time are found in accordance with the obtained equilibrium solution for ๐ก moment with the help of difference equations (6). The value of ๐ก increases by unity. Transition to the step 2. The number of reiteration of steps 2, 3, 4 is defined according to the problems of calibration, forecasting and regulation for time intervals selected in advance. Stochastic computable general equilibrium model (stochastic computable model) obtained from the deterministic model (6), (8), (9), is a model to the dynamical equation’s (6) right side of which we added an additive noise ξ(๐ก): ๐ฅ(๐ก + 1) = ๐(๐ฅ(๐ก), ๐ฆ(๐ก), ๐ง(๐ก), ๐ข(๐ก), ๐) + ξ(๐ก), ๐ก = 0, … , ๐ − 1; ๐ฅ(0) = ๐ฅ0 ๏ฌ๏ ๏ ๏จ๏ฑ๏ฐ๏ฉ๏ i.e., the model of type (10), (8), (9). We formulate the problem of variational calculus on the synthesis of the parametrical regulation optimal law for a stochastic computable model. Problem 2. Given the vector of unregulated parameters ๐ ∈ ๐ด find such regulation law ๐ข(๐ก) , which satisfies the condition (5), so that the corresponding to it the condition of the dynamical system (10), (8), (9) satisfies the following condition ๐[๐ฅ(t)] ∈ ๐1 (๐ก) × ๐2 (๐ก) × ๐3 (๐ก), ๐ก = 1, … , ๐๏ ๏จ๏ฑ๏ฑ๏ฉ๏ and provides maximum to the functional ๐พ๐ = ๐{∑๐๐ก=1 ๐น๐ก [๐ฅ(t)]}.๏ ๏จ๏ฑ๏ฒ๏ฉ๏ It is not difficult to check, that formulated above Theorems 1 and 2 hold true for the computable model with the continuous mappings ๐, ๐, โ and with convergent iterative process (8), (9). IV. COMPUTING EXPERIMENTS OF FINDING OPTIMAL VALUES OF REGULATED PARAMETERS BASED ON THE PARAMETRICAL REGULATION THEORY A. The Results of the Parametrical Identification of a Deterministic Computable Model with Knowledge Sector The considered model is presented by the following six economic agents (sectors). Sector โ 1 – sector of science and education (knowledge), which provides educational and knowledge production services. Sector โ 2 – innovative sector, representing the set of innovative-active enterprises and organizations. Sector โ 3 – other sectors of economy. Sector โ 4 – aggregate consumer, uniting households. Sector โ 5 – government. Sector โ 6 – banking sector. Here the economic sectors โ 1 – 3 are producing agents. This model is presented within: relations (6) by twelve expressions (๐1 = 12); relations (8) by 88 expressions (๐2 = 88); relations (9) by ten expressions (๐3 = 10). The examined model contains 86 exogenous parameters and 110 endogenous variables. The problem of parametrical identification of the studied macroeconomic mathematical model consists of finding estimations of unknown values of its parameters that enable to reach the minimum value of the objective function which defines deviations of output variables’ values of the model from the corresponding observed values (known statistical data). This problem reduces to finding minimum value of the objective function of several variables (parameters) in some closed domain Ω of Euclidian space under the constraints of type (7), imposed on values of endogenous variables. In the case of a large dimension of the domain of unknown parameters’ possible values, standard methods of finding extremums of functions are often ineffective due to the presence of several local minimums of the objective function. Below, we propose the algorithm that takes into account the peculiarities of the problem of parametrical identification of macroeconomic models and allows circumventing the problem of “local extremums”. For the estimation of possible values of exogenous parameters, as the domain Ω ⊂ ๐ × ๐ด × ๐1 we considered the ๐+๐ +๐ domain of Ω = ∏๐=1 1[๐๐ , ๐ ๐ ] type, where [๐๐ , ๐ ๐ ] – the interval of ω๐ parameter’s possible values; ๐ = 1, … , (๐ + ๐ + ๐1 ). Meanwhile, estimates of parameters, for which observed values existed, were searched in [๐๐ , ๐ ๐ ] intervals with centers in corresponding observed values (in case if there is one such value). Other [๐๐ , ๐ ๐ ] intervals for parameters searching were chosen with the help of indirect assessments of their possible values. In computing experiments the Nelder–Mead algorithm [6] of the directed search was applied for finding the minimum values of a continuous function ๐น: Ω → ๐ of several variables with additional constraints on endogenous variables of type (7). Application of this algorithm for the starting point ω1 ∈ Ω can TABLE I. Year ๐∗ be interpreted as a sequence {ω1 , ω2 , … } which converges to the point of local minimum ω0 = argmin ๐น of function ๐น Ω,(7) where ๐น(ω๐+1 ) ≤ ๐น(ω๐ ) ; ω๐ ∈ Ω ; ๐ = 1,2, … . While describing the following algorithm let us assume that ω0 point can be found sufficiently exactly. To solve the problem of parametrical identification of the considered computable model based on the apparent assumption of the mismatch (in general case) of minimum points of two different functions, two criteria of the following types were proposed: ๐พ๐ด (ω) = √ 1 ๐α (๐ก2 −๐ก1 +1) ๐พ๐ต (ω) = √ 1 ๐β (๐ก2 −๐ก1 +1) 2 ๐ด ∑๐ก๐ก=๐ก ∑๐๐=1 α๐ ( 1 ๐ฆ ๐ (๐ก)−๐ฆ ๐∗ (๐ก) 2 ๐ต ∑๐ก๐ก=๐ก ∑๐๐=1 β๐ ( 1 ๐ฆ ๐∗ (๐ก) ๐ฆ ๐ (๐ก)−๐ฆ ๐∗ (๐ก) ๐ฆ ๐∗ (๐ก) 2001 2002 2003 The algorithm of solution to the problem of parametrical identification of the model was selected in the form of the following steps. 1. The problems ๐ด and ๐ต (problems of a finding of the specified minima of functions ๐พ๐ด (ω) and ๐พ๐ต (ω) accordingly) are solved simultaneously for some vector of initial values of parameters ω1 ∈ Ω. As a result points ω๐ด0 and ω๐ต0 are found. 2004 2.60 2.95 3.24 3.54 3.88 ๐ 2.60 2.95 3.24 3.54 Δ๐ -0.04 0.00 0.04 0.03 ๐1∗ 0.107 0.102 0.116 ๐1 0.109 0.102 Δ๐1 1.80 -0.76 ๐2∗ 0.033 ๐2 2005 2006 2007 2008 4.26 4.72 5.14 3.88 4.26 4.72 5.15 5.26 0.04 -0.01 0.07 0.26 -0.73 0.125 0.134 0.157 0.164 0.165 0.200 0.116 0.126 0.134 0.158 0.164 0.164 0.199 -0.01 1.32 0.46 0.49 -0.02 -0.59 -0.34 0.0364 0.041 0.045 0.050 0.049 0.068 0.072 0.061 0.041 0.0343 0.039 0.044 0.050 0.049 0.067 0.071 0.061 Δ๐2 25.00 -5.86 -4.73 -2.65 -0.57 -0.19 -0.13 -0.88 0.16 ๐3∗ 2.23 2.46 2.80 3.07 3.36 3.68 4.03 4.48 4.88 ๐3 1.9 2.463 2.8 3.07 3.36 3.68 4.03 4.48 4.89 Δ๐3 ๐∗ -14.63 ๐ Δ๐ 0.00 2 ) ๏ฎ๏ ๏จ๏ฑ๏ณ๏ฉ๏ Here {๐ก1 , … , ๐ก2 } – the time span of identification; ๐ฆ ๐ (๐ก), ๐ฆ ๐∗ (๐ก) – calculated and observed values of the model’s output variables respectively; ๐พ๐ด (ω) – auxiliary criterion, ๐พ๐ต (ω) – basic criterion; ๐๐ต > ๐๐ด ; α๐ > 0 and β๐ > 0 – some weight coefficients, which values are determined by solving the problem of parametrical identification of the dynamic system; ๐๐ต ๐ด ∑๐๐=1 α๐ = ๐α ; ∑๐=1 β๐ = ๐β . OBSERVED, CALCULATED VALUES OF OUTPUT VARIABLES OF THE MODEL AND CORRESPONDING DEVIATIONS 2000 2 ) ๏ฌ๏ 5.30 0.08 0.07 0.03 0.02 0.02 0.00 0.11 0.28 106.40 106.60 106.80 106.70 107.50 108.40 118.80 109.50 106.57 106.81 106.95 106.83 107.64 108.50 118.90 109.50 0.16 0.20 0.14 0.12 0.13 0.09 0.09 0.00 2. If ๐พ๐ต (ω๐ต0 ) < ε , then the problem of parametrical identification of the model (6), (8), (9) is considered to be solved. 3. Otherwise, the problem ๐ด is solved taking the point ω๐ต0 as a starting point ω1 and the problem ๐ต is solved taking the point ω๐ด0 as a starting point ω1 . Proceed to step 2. Sufficiently large number of iterations of steps 1, 2, 3 gives an opportunity for searched values of parameters to come out from neighborhood of points of non-global minimums of one criterion with the help of another criterion and thus to solve the problem of parametrical identification. As a result of simultaneous solving of the problems A and B applying the stated algorithm with the help of the Nelder–Mead algorithm [6] the value ๐พ๐ต = 0.0073 was obtained. Meanwhile the relative magnitude of the deviations of calculated values of the variables used in the basic criteria from the corresponding observed values was less than 0.73%. The results of calculation and retrospective forecasting of the model for 2008 that are partially presented in table 1 demonstrate calculated (๐, ๐1 , ๐2 , ๐3 , ๐), observed values and deviations of calculated values of basic output variables of the model from corresponding observed values. Here the time interval 2000 – 2007 corresponds to the period of the parametrical identification of the model; year of 2008 is the period of retrospective forecasting, ๐ – gross domestic product ( × 1012 tenge, in prices of 2000); ๐๐ – gross value added of i-th sector ( × 1012 tenge, in prices of 2000; ๐ = 1,2,3); ๐ – consumer price index in percentage of the previous year; the sign “*” corresponds to the observed values; the sign “Δ ” corresponds to the deviations (in percentage) of calculated values from the corresponding observed values. B. Finding Optimal Values of Regulated Parameters Based on the Stochastic Computable Model with Knowledge Sector The stochastic computable model of economic sectors was obtained from the corresponding deterministic model (with found by solving the problem of parametrical identification estimate values of exogenous parameters) by adding a discrete Gaussian noise with independent components to the right side of all dynamical equations (6) of the model. Such equations involve the equations for calculating the following endogenous variables: - gross added values (๐1 , ๐2 , ๐3 ) of three producing sectors with the help of the corresponding productivity functions; - capital funds (๐พ1 , ๐พ2 , ๐พ3 ) of three producing sectors; - annual budgets (๐ต1 , ๐ต2 , … , ๐ต5 ) of sectors 1 – 5. Additive noises added to ๐๐ expressions can initiate corresponding cyclical fluctuations, caused by sudden shifts (shocks) in the development of technological progress and random changes in population growth. Additive noises added to ๐พ๐ expressions characterize random changes in budget shares of agents-producers assigned for a purchase of investment goods, and a random character of retirement funds coefficients. Additive noises added to ๐ต๐ expressions describe a random character of income, obtained by a sector in a current period. In this study of estimates of the average squared deviations of the generated Gaussian random variables defining the specified noise were obtained on the basis of the analysis of relevant statistical data of the Republic of Kazakhstan economy development for 2000 – 2008 in the following way. For each time series of observed values of the stated above variables we calculated sample mean square deviation of the differences between observed values and the trend of these values. Found in this way values were taken as estimates of standard deviations of components of generated discrete Gaussian noise added to the right side of the above 11 dynamic equations. In solving the stated above Problem 2 of parametrical regulation based on the stochastic computable model with knowledge sector as the optimization criterion we used the following criterion of the form (12) 1 ๐พ๐ = ๐ [ ∑2015 ๐ก=2010 ๐(๐ก)] → max๏ฎ๏ 6 ๏จ๏ฑ๏ด๏ฉ๏ Here ๐พ๐ is mathematical expectation of the average GDP of the country in prices of 2000 for 2010 – 2015. In computing experiments the calculation of the criterion ๐พ๐ was carried out in the following way. By applying the Monte Carlo method ๐ realizations of the random process ξ(๐ก) were simulated, after ๐ calculations of the model for all these simulations that are alternately used in the equations (6), average values of 1 expressions ∑2015 ๐(๐ก) on these ๐ simulations were taken 6 ๐ก=2010 as the value of ๐พ๐ criterion. Similarly, the conditions of the type (11) of endogenous variables belonging to the given domains of the phase space of the model were checked. During the experiments with the optimization criterion (14) the constraints on growth of consumer prices of the following type was used: ๐[๐(๐ก)] ≤ 1.09๐[๐ฬ (๐ก)]๏ฌ๏ ๏ ๐ก = 2010, … ,2015๏ฎ๏ ๏จ๏ฑ๏ต๏ฉ๏ Here ๐ฬ (๐ก) – calculated consumer price level of the model without parametrical regulation, ๐(๐ก) – consumer price level with parametrical regulation. In computational experiments we made regulation of 18 controlled parameters ๐๐ (๐ก) (๐ก = 2010, … ,2015; ๐ = 1, 2, 3) – consolidated budget shares assigned to subsidize the three agents-producers in 2010 – 2015. In this case the natural limitation must hold: the sum of the consolidated budget’s all eight shares used in the model (including stated above shares ๐๐ (๐ก); ๐ = 1, 2, 3) must not exceed unity: ∑8๐=1 ๐๐ (๐ก) ≤ 1๏ป๏ ๐ก = 2010, … ,2015๏ฎ๏ ๏จ๏ฑ๏ถ๏ฉ๏ The following problem of finding controlled parameters’ optimal values was considered. On the basis of a stochastic computable model with knowledge sector find ๐๐ (๐ก) values of consolidated budget’s shares assigned to three agentsproducers, which would provide an upper bound of the criterion with additional constraints (16) on these shares. The solution to this optimization problem was obtained with the help of Nelder–Mead algorithm [6]. After application of the stochastic model’s parametrical regulation of budget shares, the value of the criterion turned to be ๐พ๐ = 7.234๏1012 its value increased by 24.93% compared to the basic variant ๐พ๐ = 5.79๏1012 . An analogous problem of parametrical regulation with corresponding constraints was solved on the basis of a deterministic CGE model with knowledge sector applying ๐พ๐ criterion (deterministic analogue of the criterion (15)): 1 ๐พ๐ = ∑2015 ๐ก=2010 ๐(๐ก)๏ฎ๏ 6 After application of parametrical regulation of consolidated budget’s shares assigned to subsidize the three agentproducers, the value of the criterion of the deterministic model turned out to be ๐พ๐ = 9.23 ⋅ 1012 , the value of the criterion increased by 33.14% as compared to the basic variant. If to compare the results of the problem of the variational calculus on the basis of stochastic and deterministic computable models of general equilibrium, one can say that there is a reduction in the estimated value of the functional of the variational problem, taking into account the disturbing violations in the deterministic computable general equilibrium model in the form of additive noise. V. CONCLUSION 1. The paper presents the results on development of the parametrical regulation theory for the class of discrete stochastic dynamical systems with additive noise, and the application efficiency of the obtained results was shown by the example of one stochastic computable model with knowledge sector. 2. The effectiveness of the proposed method of parametrical identification of the deterministic model was demonstrated. 3. The method of estimating the optimal values of economic policy controlled parameters was proposed based on stochastic and deterministic variants of the computable model with knowledge sector and the corresponding estimates of the optimal control parameters were found. The obtained results can be used in the development and implementation of effective state economic policy. REFERENCES [1] [2] [3] [4] A. A. Ashimov, B. T. Sultanov, Zh. M. Adilov, Yu. V. Borovkiy, D. A. Novikov, R. V. Nizhegorodcev, and As. A. Ashimov, Macroeconomic Analysis and Economic Policy Based on Parametrical Regulation. Moscow: Physmatlit, 2010 (in Russian). ะ. ะ. Ashimov, N. A. Iskakov, Yu. V. Borovskiy, B. T. Sultanov, and As. ะ. Ashimov, “Parametrical regulation of economic growth on the basis of one-class mathematical models,” Systems Science, vol. 35, no. 1, 2009, pp. 57–63. A. A. Ashimov, K. A. Sagadiyev, Yu. V. Borovskiy, N. A. Iskakov, and ะs. A. Ashimov, “Elements of the market economy development parametrical regulation theory,” Proc. of the 9th IASTED International Conf. on Control and Applications, 2007 – Montreal, Quebec, Canada, pp. 296–301. A. A. Ashimov, K. A. Sagadiyev, Yu. V. Borovskiy, N. A. Iskakov, and As. A. Ashimov, “On the market economy development parametrical regulation theory,” Kybernetes, The international journal of cybernetics, systems and management sciences, vol. 37, no. 5, 2008, pp. 623–636. [5] [6] [7] [8] V. L. Makarov, A. R. Bakhtizin, and S. S. Sulashkin, The Use of Computable Models in Public Administration. Moscow: Scientific Expert, 2007 (in Russian). J. A. Nelder and R. Mead, “A simplex method for function minimization,” The Computer Journal, no. 7, 1965, pp. 308–313. A. A. Samarskyi and A. P. Mikhailov, Mathematical Modeling: Ideas. Methods. Examples. Moscow: Physmatlit, 2002. C. R. Nelson and C. I. Plosser, “Trends and random walks in Macroeconomic time series: Some evidence and Implications,” Journal of Monetary economics, no. 10, 1982, pp. 139–162. APPENDIX Proof of Theorem 1. According to the Weierstrass theorem, a continuous function on a nonempty closed limited set reaches its maximum. Thus, we need to show that a defined with the help of (3) the function of many variables ๐พ = ๐พ๐ (๐ข) is continuous and the set ๐๐ is closed and limited. Its nonemptiness is a part of the theorem. We show that there are mathematical value expectations in the phase constraint (4). Indeed, according to equation (1), we have ๐[๐ฅ(๐ก + 1)] = ๐[๐(๐ฅ(๐ก), ๐ข(๐ก), ๐)] + ๐[ξ(๐ก)]๏ฎ๏ The second term on the right side of this equation makes sense under the conditions of the theorem, and the first is calculated by the formula ๐[๐(๐ฅ(๐ก), ๐ข(๐ก), ๐)] = ∫๐ ๐ ๐(ω, ๐ข(๐ก), ๐)๐๐ฅ(๐ก) (ω)๐ω,๏ ๏ if the last integral is absolutely convergent (here the probability density function of a random variable ๐ฅ(๐ก) is expressed in terms of ๐๐ฅ(๐ก) ). The latter fact is indeed the case due to constraints on the growth of ๐ function and due to the existence of the mathematical expectation of ๐ฅ(๐ก) value for any ๐ก = 1, … , ๐ (this fact is verified by induction). The existence of mathematical expectation on the right side of this equation (3) follows from the constraints on growth of ๐น๐ก function and the existence of the mathematical expectation of ๐ฅ(๐ก) value. We prove its continuous dependence on ๐ข . Suppose we have the convergence of vectors ๐ข๐ → ๐ข, ๐ข๐ ∈ ๐๐ . From equation (1) it follows that |๐ฅ๐ (๐ก + 1) − ๐ฅ(๐ก + 1)| = |๐(๐ฅ๐ (๐ก), ๐ข๐ (๐ก), ๐) − ๐(๐ฅ(๐ก), ๐ข(๐ก), ๐)|๏ where ๐ฅ๐ and ๐ฅ are problem (1), (2) solutions under regulations ๐ข๐ and ๐ข respectively. Then the following relation is true |๐ฅ๐ (๐ก + 1) − ๐ฅ(๐ก + 1)| ≤ ๐ฟ๐ [|๐ฅ๐ (๐ก) − ๐ฅ(๐ก)| + |๐ข๐ (๐ก) − ๐ข(๐ก)|]๏ where ๐ฟ๐ is a Lipschitz constant of the function ๐. Repeating similar arguments and noting that, in virtue of condition (2), ๐ฅ๐ (0) = ๐ฅ0 , we have |๐ฅ๐ (๐ก + 1) − ๐ฅ(๐ก + 1)| ≤ (๐ฟ๐ )2 |๐ฅ๐ (๐ก − 1) − ๐ฅ(๐ก − 1)|๏ +(๐ฟ๐ )2 |๐ข๐ (๐ก − 1) − ๐ข(๐ก − 1)| + ๐ฟ๐ |๐ข๐ (๐ก) − ๐ข(๐ก)|๏ ≤ ∑๐ก๐ =0(๐ฟ๐ ) ๐ +1 |๐ข๐ (๐ก − ๐ ) − ๐ข(๐ก − ๐ )| ≤ ε๐ ๏ ๏ where ε๐ → 0 when ๐ → ∞. Denoting the maximum of the Lipschitz constant of ๐น๐ก functions, for ๐ก = 1, … , ๐ through ๐ฟ๐น we get the estimate |๐น๐ก [๐ฅ๐ (๐ก)] − ๐น๐ก [๐ฅ(๐ก)]| ≤๐ฟ๐น ε๐ ๏ฎ๏ Taking into account f-continuity of the family of sets {๐๐ } and continuity on ๐ด × ๐ of the function ๐๐ (๐ฅ), we conclude that for any value of ๐ > 0 there is such a number of ๐0 , so that when ๐ > ๐0 there are points ๐ฅ′๐ ∈ ๐๐0 for which the inequalities |๐๐๐ (๐ฅ′๐ ) − ๐๐๐ (๐ฅ๐ )| ≤ ε hold and also max|๐๐๐ (๐ฆ) − ๐๐ะพ (๐ฆ)| ≤ ε. ๐ฆ∈๐ As a result, when ๐ > ๐0 , we get the following inequalities ๐๐0 (๐ฅ0 ) ≥ ๐๐0 (๐ฅ ′ ๐ ) ≥ ๐๐๐ (๐ฅ ′ ๐ ) − ๐ ≥ ๐๐๐ (๐ฅ๐ ) − 2ε๏ฎ๏ ๏จ๏ฑ๏ท๏ฉ๏ Having calculated the mathematical expectation of both sides of this inequality, we obtain the inequality The following relation is checked in the same way: ๐๐๐ (๐ฅ๐ ) ≥ ๐๐0 (๐ฅ0 ) − 2ε๏ฎ๏ ะ{|๐น๐ก [๐ฅ๐ (๐ก)] − ๐น๐ก [๐ฅ(๐ก)]|}≤๐ฟ๐น ε๐ ๏ฎ๏ It follows that ะ{|๐น๐ก [๐ฅ๐ (๐ก)] − ๐น๐ก [๐ฅ(๐ก)]|}→0 and convergence of the considered sequence ๐{๐น๐ก [๐ฅ๐ (๐ก)]} → ๐{๐น๐ก [๐ฅ(๐ก)]}. Hence, (3) implies the continuity of the functions ๐พ๐ from ๐ข. Limitation of the set ๐๐ follows from the limited set ๐(๐ก). Closure of the set ๐๐ follows from the continuous mapping ๐๐ → ๐, set with the help of definition of the set ๐๐ and compactness of the set ๐ (the theorem on the closure of a complete preimage of a compact under the continuous mapping). Now the existence of problem solution follows from the Weierstrass theorem. The theorem is proved. Tentatively we formulate the following definition and auxiliary statement used in the proof of Theorem 2. Definition. Let the family of function ๐๐ (๐ฅ), ๐ ∈ ๐ด, ๐ฅ ∈ ๐ be defined for the family of subsets {๐๐ } of some set ๐ of Euclidian space with the parameter ๐ from some subset ๐ด of Euclidian space. The family {๐๐ } is f-continuous on the set ๐ด, if for any ε > 0 there is a number δ > 0 , so that when performing the inequality |๐ − ๐| ≤ δ, ๐, ๐ ∈ ๐ด for any ๐ฅ๐ ∈ ๐๐ there is such point ๐ฅ๐ ∈ ๐๐ , so that |๐๐ (๐ฅ๐ ) − ๐๐ (๐ฅ๐ )| < ε inequality holds. ๏จ๏ฑ๏ธ๏ฉ๏ From (14) and (15) it follows that under sufficiently large values of ๐ the relation |๐๐๐ (๐ฅ๐ ) − ๐๐0 (๐ฅ0 )| ≤ 2ε , which provides the convergence of the sequence ๐๐๐ (๐ฅ๐ ) → ๐๐0 (๐ฅ0 ) , is true. The lemma is proved. Proof of Theorem 2. In the proof of Theorem 1 we established that sets ๐๐ are closed and bounded and ๐พ๐ function is continuous. There we also established continuity of the mapping ๐ข → ๐[๐ฅ๐๐ข (๐ก)] from which the ๐พ๐ -continuity of the family of sets follows. Here ๐ฅ๐๐ข (๐ก) denotes the solution of the system (1), (2) for selected ๐ and ๐ข. We show the uniform on ๐ข continuity of the mapping ๐ → ๐พ๐ (๐ข). Suppose that there is convergence ๐๐ → ๐ From the condition (1) we get the following estimate |๐ฅ๐๐ข๐ (๐ก + 1) − ๐ฅ๐๐ข (๐ก + 1)| = |๐(๐ฅ๐๐ข๐ (๐ก), ๐ข(๐ก), ๐๐ )๏ −๐(๐ฅ๐๐ข (๐ก), ๐ข(๐ก), ๐)| ≤ ๐ฟ๐ [|๐ฅ๐๐ข๐ (๐ก) − ๐ฅ๐๐ข (๐ก)| + |๐๐ − ๐|]๏ where ๐ฟ๐ is the Lipschitz constant of ๐ function. Given the initial state of the system, we obtain the inequality |๐ฅ๐๐ข๐ (๐ก) − ๐ฅ๐๐ข (๐ก)| ≤ ∑๐๐ =1(๐ฟ๐ )๐ |๐๐ − ๐|.๏ ๏ According to this definition the family of sets {๐๐ } is ๐continuous, if in the case of enough proximity of the parameter ๐ to ๐, for any element from the set ๐๐ there is arbitrarily close (for a function value) to it element of the set ๐๐ . Let ๐ฟ๐น denote the maximum of Lipschitz constants of ๐น๐ก function. Then the following estimate is true The following lemma is auxiliary to prove the continuity of optimal values of the problems of variational calculus on the synthesis of optimal laws of parametrical regulation. |๐น๐ก [๐ฅ๐๐ข๐ (๐ก)] − ๐น๐ก [๐ฅ๐๐ข (๐ก)]| ≤ ๐ฟ๐น |๐ฅ๐๐ข๐ (๐ก) − ๐ฅ๐๐ข (๐ก)| ≤ ๐ฟ๐น ∑๐๐ =1(๐ฟ๐ )๐ |๐๐ − ๐|.๏ ๏ Lemma 1. Let ๐ด and ๐ be some subsets of Euclidian spaces, ๐ compact; the family of closed subsets {๐๐ } belongs to ๐ . Let the mapping (๐, ๐ฅ) → ๐๐ (๐ฅ) be continuous in the product of ๐ด × ๐ . Let the family of subsets {๐๐ } be ๐ continuous in ๐ด . Then the mapping ๐ → max ๐๐ (๐ฅ) is Having proceeded to the mathematical expectations of the right and left sides in the last inequality, we obtain that ะ{|๐น๐ก [๐ฅ๐๐ข๐ (๐ก)] − ๐น๐ก [๐ฅ๐๐ข (๐ก)]|}→0. It follows that, when ๐ → ∞ for any ๐ก = 1, … , ๐ there are convergence ะ{๐น๐ก [๐ฅ๐๐ข๐ (๐ก)]}→ะ{๐น๐ก [๐ฅ๐๐ข (๐ก)]} uniformly on ๐ข from the sum of all sets ๐๐ and hence, uniform on ๐ข continuity of the mapping ๐ → ๐พ๐ (๐ข) and continuity on (๐, ๐ข) of the function ๐พ๐ (๐ข) . Having applied Lemma 1 we obtain the desired result. The theorem is proved. continuous in ๐ด. ๐ฅ∈๐๐ Proof of Lemma 1. Suppose we have a convergence of a sequence ๐๐ → ๐0 , where ๐0 , ๐๐ ∈ ๐ด Let ๐ฅ๐ denote the maximum point of the function ๐๐๐ on the set ๐๐๐ , and ๐ฅ0 – the maximum point of the function ๐๐0 on the set ๐๐0 .