Distributions of stopping times in some sequential estimation procedures

A class of sequential estimation procedures is considered in the case when relevant data may become available only at random times. The exact distributions of the optimal stopping time and the number of observations at the moment of stopping are derived in some sequential procedures. The results obtained in an explicit form are applied to derive the expected time of observing the process, the average number of observations and the expected loss of sequential estimation procedures based on delayed observations. The use of the results is illustrated in a special model of normally distributed observations and the Weibull distributed lifetimes. The probabilistic characteristics are also derived for an adaptive sequential procedures and the behavior of the adaptive procedure is compared with the corresponding optimal sequential procedure.     

Dependencies between price duration,volatility, volume and return on the Warsaw Stock Exchange

The successive changes of asset prices are the most visible manifestation of financial markets dynamics. There exist different views about factors generating these changes, but many researchers and practitioners agree that the most important among them is the impact of information flow. According to the market microstructure theories, it depends mainly on the behavior of informed and uniformed traders. In the paper, we investigate dependencies between the possible proxies of information process： price duration and corresponding to it volume change and return. Our main objective is to answer the question about the most important factor in the process of discovering information by uniformed traders. We apply a set of models for volatility, volume and duration data. Our analysis is performed for selected equities listed on the Warsaw Stock Exchange and uses tick-by-tick data. The obtained results show that the stock liquidity on this leading stock market in Central and Eastern Europe is the most important factor influencing the process of discovering information by uninformed traders.     

Public Expenditure in Poland: Major Trends,Challenges and Policy Concerns

This article surveys the behaviour of public expenditure in Poland. The analysis is conducted against a theoretical background outlining the basic government functions and possible government failures in a market economy. The first part provides an overview of major trends in public expenditure during systemic transformation in Poland. It also highlights the reprioritisation of government objectives in channelling budgetary funds. The second part gives an account of the most salient consequences of the changing pattern of public expenditure and discusses the main policy concerns involved, pointing out the adverse macroeconomic effects of government failure to create or enhance positive externalities for business. The last part outlines the most significant future challenges, with special emphasis on the implications of the public finance crunch that emerged in mid-2001. It also argues that two 'external' factors, globalisation and the forthcoming EU accession, will gain importance in the future in shaping public expenditure in Poland.     

Interfunctional dynamics and firm performance: A comparison between firms in Poland and the United States

This study compares between firms in the US mature market economy and in the Polish transitional economy. The study found that Poland's past as a planned economy may continue to hinder interdepartmental connectedness and act as an obstacle to firms in adopting a market orientation. According to the study, for Polish firms, there is less shared information and cooperation across departments, and less shared responsibility for departmental tasks, compared to US firms. The status of marketing in Poland remains that of a junior department, subordinate to influences from functional areas such as finance and accounting, which directed production in the former planned economy. The study supports the hypothesis that Polish firms have lower interdepartmental connectedness than US firms and finds strong support for the relationship between interdepartmental connectedness and firm performance.     

Financial Inflows to Poland, 1990–96

Foreign exchange flows in Poland in the 1990s, especially during 1994–96, resulted from two developments. First, there was a current account surplus, as growth revived due to efficiency improvements, while macroeconomic policy limited domestic demand. Second, Poland had rejoined international capital markets and regained favorable credit ratings, triggering investment inflows. We can classify the effects of these inflows into three groups: changes in the institutional framework; changes in the stabilization path; and changes in the real economy. The crawling band introduced in May 1995, rapid development of the money market, and improvement of the central bank's capacity to intervene on that market are in the first group. As to the second, relative currency appreciation and import competition, constraining domestic price increases, contributed to the strong disinflationary push which began in 1995. Under the third heading, foreign direct investment and portfolio inflows helped to maintain rapid growth of investment and output.     

Minimax estimation of a cumulative distribution function by converting to a parametric problem

Let X = (X ₁,...,X _n ) be a sample from an unknown cumulative distribution function F defined on the real line . The problem of estimating the cumulative distribution function F is considered using a decision theoretic approach. No assumptions are imposed on the unknown function F. A general method of finding a minimax estimator d(t;X) of F under the loss function of a general form is presented. The method of solution is based on converting the nonparametric problem of searching for minimax estimators of a distribution function to the parametric problem of searching for minimax estimators of the probability of success for a binomial distribution. The solution uses also the completeness property of the class of monotone decision procedures in a monotone decision problem. Some special cases of the underlying problem are considered in the situation when the loss function in the nonparametric problem is defined by a weighted squared, LINEX or a weighted absolute error.     

Dynamic linkages between stock markets: the effects of crises and globalization

This paper investigates changes in the dynamics of linkages between selected national stock markets during the period 1995–2009. The analysis focuses on the possible effects of globalization and differences between crisis and non-crisis periods. We model the dynamics of dependencies between the series of daily returns on selected stock indices over different time periods, and compare strength of the linkages. Our tools are dynamic copula models and a formal sequential testing procedure based on the model confidence set methodology. We consider two types of dependencies: regular dependence measured by means of the conditional Spearman’s rho, and dependencies in extremes quantified by the conditional tail dependence coefficients. The main result consists of a collection of rankings created for the considered subperiods, which show how the mean level of strength of the dependencies have been changing in time. The rankings obtained for Spearman’s rho and tail dependencies differ, which allows us to distinguish between the results of crises and the effect of globalization.