Suheyla Ozyildirim

A note on price-volume dynamics in an emerging stock market

Abstract We present a continuum economy with risk neutral agents having heterogeneous expectations and restricted short sales. A stochastic version of the model is also formulated and the resulting time series behavior of the price and volume series under a specific money supply process derived. The implications of the model are tested in the emerging Turkish stock market where institutional arrangements comply with the restrictions of the model. The results indicate that, as predicted by the model, price levels and trading volume are cointegrated. The error correction models are also estimated and found to be significant in most cases.

A genetic game of trade, growth and externalities

Abstract A genetic algorithm is introduced to search for optimal policies in the presence of knowledge spillovers and local pollution in a dynamic North/South trade game. Non-cooperative trade compounds inefficiencies stemming from externalities. Cooperative trade policies are efficient and yet not credible. Short of a joint maximization of the global welfare, transfer of knowledge remains as a viable route to improve world welfare.

Income Inequality and Economic Convergence in Turkey: A Spatial Effect Analysis

Even though the convergence of regional per capita income has been a highly debated issue internationally, empirical evidence regarding Turkey is limited as well as contradictory. This article is an attempt to investigate regional income inequality and the convergence dynamics in Turkey for the time period 1987—2001. First, the Theil coefficient of concentration index is used to analyze the dispersion aspects of the convergence process. The geographically based decomposition of inequality suggests a strong correlation between the share of interregional inequality and spatial clustering. Then, we estimate convergence dynamics employing alternative spatial econometric methods. In addition to the global models, we also estimate local models taking spatial variations into account. Empirical analysis indicates that geographically weighted regression improves model fitting with better explanatory power. There is considerable variation in speed of convergence of provinces, which cannot be captured by the traditional beta convergence analysis.

Learning the optimum as a Nash equilibrium

This paper shows the computational benefits of a game theoretic approach to optimization of high dimensional control problems. A dynamic noncooperative game framework is adopted to partition the control space and to search the optimum as the equilibrium of a k-person dynamic game played by k-parallel genetic algorithms. When there are multiple inputs, we delegate control authority over a set of control variables exclusively to one player so that k artificially intelligent players explore and communicate to learn the global optimum as the Nash equilibrium. In the case of a single input, each players decision authority becomes active on exclusive sets of dates so that k GAs construct the optimal control trajectory as the equilibrium of evolving best-to-date responses. Sample problems are provided to demonstrate the gains in computational speed and accuracy.

Computing open-loop noncooperative solution in discrete dynamic games

Abstract.The purpose of this paper is to introduce a new algorithm for the approximation of non-quadratic, non-linear open-loop Nash Cournot equilibrium in a difference game of fixed duration (multiperiod) and initial state. The algorithm based on adaptive search procedure called genetic algorithm has been used to optimize strategies for N-person dynamic games. Since genetic algorithms require little knowledge of the problem itself, computations based on these algorithms are very attractive to complex dynamic optimization problems. The empirical evidences are also provided to show the success of the algorithm developed. A typical example in US macroeconomic policy selection for 1933-1936 yields evidence of political inference in the economy.

Optimal versus adequate level of international reserves: evidence for Turkey

The determination of international reserve balance for emerging economies is part of the efforts to strengthen the immunity of these economies to crises. However, there is still evidence on crises even for the countries with large foreign reserves. It has usually been experienced that the countries with greatest need for reserves economize more than others on their holdings since they might underestimate the cost of crisis. In this study, the official international reserves of Turkey are tested against optimality and adequacy. During 1988–2002, the actual reserves fell short of both the optimal and the adequate levels. They are only optimal when the expected cumulative contraction is about 5.2% of real GDP under crisis. However, early evidence from emerging economies and Turkey show that crises hit more heavily. Hence, it is found that the current financial structure in Turkey such as the absence of capital controls and a highly dollarized banking system necessitates more foreign reserves for preventing any future economic and/or financial shocks.

Three-country trade relations: A discrete dynamic game approach

Abstract A three-country, two-bloc trade model is used to determine the impact of a coalition within the blocs on the optimal pricing policies of the bloc. It is shown in a North-South world where the South has to cooperate for efficient pricing policy. In addition to the complexities of interactions between three countries, a dynamic game approach leads to the usage of numerical methods in this paper. We used a new algorithm based on adaptive search procedure called genetic algorithm to optimize strategies for three-person discrete dynamic games. Welfare implications are also addressed.

Political Connection, Bank Credits and Growth: Evidence from Turkey

The pervasive existence of government‐owned banks in emerging economies is often justified by their provision of access to credit in remote and underdeveloped regions that are ignored by private banks. This paper analyses whether credits provided by government‐owned and private banks have a significant role in regional growth and whether this role changes in politically connected areas in Turkey. Our findings imply that private banks significantly improve the economic well‐being in all Turkish provinces regardless of their development level or their political connection with the ruling party. However, credits by government‐owned banks are found to be positively related to the per capita growth rate only in the less developed provinces that are advocates of the ruling political party and also developed but not politically connected provinces. These results suggest that government‐owned bank credits, as implied by the political view, are used for funding politically desirable projects or politically connected borrowers.

Bank Quality, Loan Demand, and Market Discipline

In this paper, we examine the disciplinary role of borrowers, who are one of the key stakeholders in Turkish banks and are heavily affected when their banks experience difficulty. In the theoretical model, we show that borrowers prefer to have a relationship with less risky banks although it increases their cost of getting funds. Empirically, we examine the relationship between quality of a bank and its loan demand and find that as riskiness of a bank decreases, its loan demand increases significantly, suggesting the disciplinary role of borrowers in Turkey.

How Sensitive are Shareholders to Bank Risk

We test for the existence of market discipline of banks by different types of shareholders. Shareholder discipline manifests itself in the form of monitoring the riskiness of banks as well as influencing the management actions of the banks to limit risk-taking. Shareholders utilize different types of risk measures to monitor bank risk taking. Shareholders influence bank management to improve capital adequacy and loan quality when they observe increasing riskiness. Owner-managers or large shareholders demonstrate significant influence on bank management. We also find that the influence on management in small banks by shareholders is more pronounced.