On kalman filtering,posterior mode estimation and fisher scoring in dynamic exponential family regression

Summary Dynamic exponential family regression provides a framework for nonlinear regression analysis with time dependent parametersβ ₀,β ₁, …,β _t, …, dimβ _t=p. In addition to the familiar conditionally Gaussian model, it covers e.g. models for categorical or counted responses. Parameters can be estimated by extended Kalman filtering and smoothing. In this paper, further algorithms are presented. They are derived from posterior mode estimation of the whole parameter vector (β′₀, …,β′_t) by Gauss-Newton resp. Fisher scoring iterations. Factorizing the information matrix into block-bidiagonal matrices, algorithms can be given in a forward-backward recursive form where only inverses of “small”p×p-matrices occur. Approximate error covariance matrices are obtained by an inversion formula for the information matrix, which is explicit up top×p-matrices. Heinz Leo Kaufmann, my friend and coauthor for many years, died in a tragical rock climbing accident in August 1989. This paper is dedicated to his memory.     

On existence and uniqueness of maximum likelihood estimates in quantal and ordinal response models

Summary For quantal and ordinal response models, conditions on existence and uniqueness of maximum likelhood estimates are presented. Results are derived from general results on direction sets and spaces associated with a proper concave function. If each summand of the log likelihood is in any direction either strictly concave or affine, necessary and sufficient conditions are obtained. If all cell counts are strictly positive, then it is shown that estimates always exist, and that they are unique if all parameters are identifiable. If estimates exist without being unique, results on uniquely estimable linear functions are given, paralleling corresponding results in linear regression. An extension of the maximum likelihood principle is outlined yielding similar results even if the likelihood does not attain its supremum. The logit model, the linear probability model, cumulative and sequential models and binomial response models are considered in detail.     

Structural breaks in Austrian foreign trade with Eastern Europe during the early 1970s

Between 1955 and 1987, Austrian trade with Eastern Europe was characterized by specific factors. On the one hand, trade flows were influenced by the central planning system in Eastern Europe. On the other hand, Austria applied non-standard policy tools to manage Eastern trade. Furthermore, Austrian trade with Eastern Europe was affected by the implementation of the free trade agreement with the European Communities (EC) and the change in the institutional framework for Eastern trade in the early 1970s. Austrian Eastern exports were fostered by increased export subsidies and barter trade. We assess the net effects of these contradictory measures of trade policy by estimating aggregate import and export equations and testing for a structural break in 1973. Our results are consistent with the view that Austria subsidized Eastern exports to pursue a countercyclical policy after 1973.

Die ökonomischen Grundbegriffe

Ohne Zusammenfassung     

Greasing the Wheels of Trade: A Profile of the Dutch Transaction Sector***

How many resources does a nation spend on transactions costs to ‘grease the wheels of trade’? To examine this question the Dutch economy is used as a case study. The Netherlands are known as a nation of traders and this image was derived in the seventeenth century from successes in long distance trade, shipping and financial innovations. Despite its historical background the trading sector has never been adequately measured. In this paper, we present a first attempt in measuring and describing the Dutch transaction sector. Measurement by means of occupational data points out that approximately 25% of Dutch workers is employed in transaction jobs, and 29% if one includes transport tasks. We make the case that traditional industrial sector categories overestimate the true transaction character of an economy. Traditional ‘trade’ sectors employed 13% of the workers in 1807 and 39 percent in 1998, but these figures conceal the fact that all organizations employ jobs which have transformation and transaction tasks. A counterfactual exercise suggests that the growth of the transaction sector share in employment over two centuries was not 200% but 42%.     

STRATEGIES OF EXPANSION AND ORGANIZATIONAL DEVELOPMENTS IN EUROPEAN AND AMERICAN FIRMS 1

Summary The pace of change of the last ten years has challenged the traditional management processes to the point that the key organizational question is no longer to fit new strategies into available organizational patterns but instead to fit the organizational structure to the kind of problems to be faced. However, the intricacy of strategic and structural difficulties is often such that the appraisal of organizational inadequacies may prove difficult: symptoms may be wrongly considered as problems which may in turn be over-or understated so that corrective measures may well be inappropriate. This is why the saying‘When in trouble, reoganize!’is of little practicability. The lack of organizational planning in framing responses to structural problems will more and more make adjustments necessary. In our attempts to define the nature of organizational changes which are likely to occur within business firms in the future, we shall isolate the stragetic decisions related to corporate expansion on a transnational, trans-continental and eventually on an intercontinental scale. We shall start by analysing present organizational patterns — as they reflect decisions made in the past regarding current strategies — and we shall try to outline some possible structural developments as they may be required by the implementation of future strategies.     

Robust planning: a new paradigm for demand chain planning

This paper proposes a new paradigm for tactical demand chain planning (DCP), called robust planning, based on risk assessment of the supply and demand chain. The concepts of supply chain management (SCM), and its extension demand chain management (DCM), have been at the center of much recent research. One of the reasons for this is that, over the last years, a significant number of information systems have emerged, which claim to support the concept. The paper argues that these systems mostly adopt a myopic view of planning, based on pure deterministic planning methods. It demonstrates that such an approach fails to coop with the considerable uncertainty of the planning information. The proposed robust planning paradigm is then introduced and its impact explained, using the well-known example of the beer game. It holds the promise of reducing the number of re-planning cycles, through a better characterization of the expected service level performance over a medium planning horizon. Finally, a case study will show the value of robust planning in a European chemical enterprise.     

Tax rates as strategic substitutes

This paper analytically derives conditions under which the slope of the tax-reaction function is negative in a classical tax competition model. If countries maximize welfare, a negative slope (reflecting strategic substitutability) occurs under relatively mild conditions. The strategic tax response is crucial for understanding tax competition games, as well as the welfare effects of partial tax unions (whereby a subset of countries coordinate their tax rates). Indeed, contrary to earlier findings that have assumed strategic complementarity in tax rates, we show that partial tax unions might reduce welfare under strategic substitutability.     

It's alright,it's just a bluff: Why do corporate codes reduce lying,but not bluffing?

Purchasing operates in an environment that frequently provides incentives for deception. Using self-concept maintenance theory and social learning theory, this article compares two distinct manifestations of deception in buyer–supplier negotiations: lying and bluffing. Scenario-based experiments provide evidence that corporate codes diminish severe manifestations of deception (lying) but not less severe ones (bluffing), and that bluffing is considered a negotiation skill. These findings reveal the boundary conditions of self-concept maintenance theory, which is applicable to lying but not to bluffing. Moreover, this article outlines an agenda for future research on deception in buyer–supplier relationships – an important but under-researched subject within our discipline.     

A framework for selection of strategy for management of security measures

In this paper, we present and discuss a framework for security risk management, focusing on the selection of a management strategy for decision-making on security measures in particular. The framework provides guidance on the selection of a suitable type of management strategy for various types of decision-making contexts. An Information and Communication Technology case study is used to illustrate the practical implications of the framework.