Specialization, Information, and Growth: A Sequential Equilibrium Analysis


Yew-Kwang Ng

Department of Economics
Monash University

And

Xiaokai Yang

Department of Economics, Monash University and
Center for International Development, Harvard University

* The authors are grateful to the referee for Review of Development Economics, Jeff Borland, Bob Rice, and participants of an AEA session on development economics and of International Symposium on Dynamic Modeling for helpful comments. Financial support from Australia Research Council is gratefully acknowledged. We are responsible for any remaining errors.


Abstract

Pricing costs and information problems are introduced into a framework with consumer-producers, economies of specialization, and transaction costs to predict the endogenous and concurrent evolution in division of labor and in the information of organization acquired by society. The concurrent evolution generates endogenous growth based on the tradeoff between gains from information about the efficient pattern of division of labor, which can be acquired via experiments with various patterns of division of labor, and experimentation costs, which relate to the costs in discovering prices. The concept of Walras sequential equilibrium is developed to analyze the social learning process which is featured with uncertainties of the direction of the evolution as well as a certain trend of the evolution.

Introduction

The purpose of the paper is two fold. First, it shall explore the implications of interactions between evolution in division of labor and evolution in information about the efficient pattern of division of labor that is acquired by society through the price system for economic growth. Second, we shall develop the notion of Walrasian sequential equilibrium to model concurrent evolution in division of labor and in information of organization acquired by society.

Recent development of endogenous growth model, represented by Judd [1985], Romer [1990], Grossman and Helpman [1989], and Yang and Borland [1991] not only explains economic growth by endogenous accumulation, but also explains growth by evolution in division of labor which generates increases in the number of goods and in individuals' levels of specialization as two aspects of economic development. The spontaneous evolution in division of labor in the models not only generates growth phenomena (growth in per capita real income, in productivity, and in per capita consumption) in the absence of exogenous changes in parameters, but also generates development phenomena, such as increases in individuals' levels of specialization, in the number of traded goods, in the degree of market integration, in the degree of diversification of economic structure, in the number of markets, in income share of transaction costs, and so on. In contrast, neoclassical growth models, represented by Ramsey [1928], can only generate evolution in per capita real income or in per capita consumption, although they may generate endogenous growth in the absence of exogenous changes in parameters, as shown by Barro and Sala-i-Martin [1995].

However, evolution in division of labor in the literature of endogenous growth is generated by a deterministic mechanism based on individuals' dynamic decisions with infinite horizon. This evolutionary process involves no uncertainties. As Nelson [1995] points out, real economic growth process is an evolutionary process that is featured with uncertainties of the direction of the evolution and with a certain trend of the evolution. The first purpose of the present paper is to develop an endogenous growth model that generates an evolutionary process of division of labor, characterized by the two features.

Since productivity depends on the level and pattern of division of labor that is chosen by individuals while information about the efficient level and pattern of division of labor acquired by society determines which level and pattern of division of labor will be chosen, the dynamic nature of the information acquisition is essential for us to understand economic development. As shown by Yang and Ng [1993], an individual's decision on his level and pattern of specialization is always a corner solution. As he changes his level of specialization, he discontinuously jumps from a corner solution to another corner solution. Hence, a person can only use total benefit-cost analysis to identify the optimum corner solution after he has conducted marginal analysis of each corner solution. The discontinuity of decision variables across corner solutions generates two kinds of complexities. Suppose it takes a period of time for a person to try a corner solution, then for a given set of prices, a person can sort out the optimum corner solution only after a sufficiently large number of periods. However, market prices that are available are determined by each and every individuals' decisions to choose a certain corner solutions. For instance, no market prices will be available if all individuals choose an autarkic corner solution that involves no trade (that is, quantities of traded goods are 0). Hence, individuals' decisions to choose corner solutions determine what information on prices is available, while the information determines individuals' decisions in choosing their levels and patterns of specialization (or in choosing corner solutions). When time dimension is spelt out, the interactions between information and dynamic decisions will generate concurrent evolution in information about the efficient pattern of organization acquired by society and evolution in the level of division of labor that is chosen by individuals.

An example may illustrate the nature of the information acquisition process. Founding of McDonald restaurant network can be considered as an experiment with a pattern of high level of division of labor between specialized production of management and planning and specialized production of direct services within the franchise and between specialized production of food and specialized production of other goods. Since all variables and demand and supply functions are discontinuous from corner solution to corner solution, marginal analysis based on interior solutions cannot provide the founder of this franchise with the information for right decision. The founder of McDonald restaurant network decided to use the market to experiment with his new pattern of business organization that involves a higher level of division of labor within the franchise and between the franchise and the rest of the economy. Instead of adjusting prices at the margin, he tried a price of restaurant services that was much lower than the prevailing price of restaurant services. According to his calculation, the higher level of division of labor would generate productivity gains, on the one hand, and more transaction costs, on the other. His franchise arrangements may reduce transaction costs to the extent that the benefit of the higher level of division of labor outweigh its cost, so that the substantially lower price of services can stand with the test of the social experiment. This idea was substantiated later, as we have seen in real world. However, the founder may go to bankruptcy if the business was proved by the social experiment to be inefficient compared to the prevailing pattern of organization prior to the experiment. But the social experiment through the price system is necessary for society to acquire the information about the efficient pattern of division of labor, even if it generates business failure because of the interdependency between decisions in choosing a pattern of organization and available information of prices and because of discontinuity of decision variables between different patterns of division of labor.

Kreps and Wilson's concept of sequential equilibrium might be a vehicle for analyzing the interactions between dynamic strategies and information. However, it is a formidable job to endogenize evolution in division of labor in addition to endogenization of the interactions between dynamic decision and information using their concept. Usually, even without the endogenization of evolution of division of labor, only extremely simple models of sequential equilibrium can be solved. Hence, the second purpose of the paper is to develop the concept of Walrasian sequential equilibrium that makes modeling of endogenous evolution in division of labor and evolution in information of organization tractable. The concurrent evolution in division of labor and in information acquired by society through the price system are based on adaptive behavior and on limited horizon, so that it is closer to a real economic development process than what is predicted by Romer [1990] and Yang and Borland's endogenous growth models [1991] with spontaneous evolution in division of labor based on perfect information and infinite decision horizon. Somehow, the present paper bridges the literature of endogenous growth and the literature of bounded rationality (see Conlisk [1996] for a recent survey on the latter literature).

In the model to be considered, there are many ex ante identical consumer-producers with preferences for diverse consumption and production functions displaying economies of specialization. Complicated interactions between economies of specialization and transaction costs in the market generate uncertainties about real income for different patterns of division of labor. Each person's optimal decision is a corner solution. Combinations of different corner solutions generate many possible candidates (corner equilibria) for general equilibrium. Individuals may experiment with each possible pattern of division of labor via a Walrasian auction mechanism at a point in time and thereby eliminate uncertainties and acquire information about the efficient pattern of division of labor over time. However, the costs in discovering prices generate a tradeoff between information gains and experimentation costs in the information acquisition process. A decentralized market will trade off gains from information acquisition against experimentation costs to determine the equilibrium pattern of experiments with patterns of division of labor over time. In the process, individuals use Bayes' rule and dynamic programming to adjust their beliefs and behavior according to updated information. Hence, we refer to the solution to the model as Walras sequential equilibrium. The determinants of the dynamics of the Walras sequential equilibrium are transportation cost coefficient for trading one unit of goods, degree of economies of specialization, discount rate, and pricing cost coefficient.

Suppose the transportation cost coefficient and the degree of economies of specialization are fixed. If pricing costs are high, then the market will not experiment with any sophisticated pattern of division of labor. If pricing costs are sufficiently low, all possible patterns of division of labor will be experimented with. In this process, simple patterns of division of labor are experimented with before the more complicated ones are, so that a gradual evolution of division of labor may occur. If pricing costs are at an intermediate level, then only simple patterns of division of labor will be experimented with, so that society cannot acquire all information about the efficient economic organization. For a fixed pricing cost coefficient, more patterns of division of labor will be experimented with as the transportation cost coefficient decreases and/or as the degree of economies of specialization increases.

Our concept of Walras sequential equilibrium is an analogue to Kreps and Wilson's concept of sequential equilibrium. In the game model of Kreps and Wilson [1982], players use dynamic programming to choose strategies for a given sequence of their beliefs of their opponents' types and the sequence of beliefs is updated according to the Bayes rule and the observed strategies. In our model, individuals use dynamic programming to solve for their experimentation sequence with different patterns of division of labor for given information of the ranking of each person's incomes generated by various patterns of specialization. The information is updated according to the Bayes rule and observed prices. The difference between our concept of Walras sequential equilibrium and Kreps and Wilson's concept of sequential equilibrium will be discussed in section 3.

Compared to Again et al [1991], the result in this paper is more limited to a specific model because the discontinuity of payoff functions in a general equilibrium model based on corner solutions makes intractable a model that is as general as Aghion's. Because of corner solutions and discontinuity of payoff functions across corner solutions, we assume the absence of information in this paper, while incomplete information is assumed in Aghion et al. An experimentation cost in addition to the discount rate is specified as generated by the process of discovering prices. By contrast, the experimentation cost in Aghion et al is generated only by the discount rate. Finally, our model is a general equilibrium model while Aghion's model is a partial equilibrium model. This makes our model more difficult to manage, so that we confine attention to a specific model where all individuals' decisions on learning by experimenting with the patterns of economic organization are symmetric. The symmetry avoids the problem of coordination and mismatch in experimentation with various patterns of the division of labor, thereby keeping the model tractable at the cost of realism. We leave the analysis of a more realistic model with the coordination problem caused by information asymmetry, which may generate interesting implications of the role of entrepreneurship in experiments with economic organization, to future research.

This paper is organized as follows. Section 1 specifies an equilibrium model that endogenizes the determination of the efficient pattern of the division of labor in a Walrasian regime. Section 2 introduces a pricing cost and the information problem into the model to generate a story about learning by experimenting with various patterns of the division of labor. Section 3 solves for the dynamic equilibrium and discusses the implications of the results.

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