Testing for autocorrelation among common stock returns

We consider the null distribution of autocorrelation coefficients for stock returns when the variance of the returns is infinite. We show that the empirical autocorrelations then tend to zero faster than in the standard case and that they tend, after suitable normalisation, in distribution to a rather complicated nonnormal law. An empirical application to the 14 most busy German stocks reveals that the significance of observed correlations is thereby in general reduced.     

The demographic effect of mixed marriages

This paper gives a formal expression for the demographic effect of mixed marriages; i.e., the effect on the number of children, and thereafter illustrates the long-term effects of these marriages with a simple simulation model     

PROPERLY RESCALED COMPONENTS OF SMOOTH TESTS OF FIT ARE DIAGNOSTIC

The paper illustrates a typical pitfall associated with a conventional interpretation of components of smooth tests of fit, for example the first nonzero components of the smooth tests for Poissonity, exponentiality, normality and the geometric distribution. In order to achieve a directed diagnosis concerning the kind of departure from a hypothesised model, an appropriate rescaling of components is necessary.     

Adopting the Municipal Enterprise Form in Finland: Core Dilemmas in the Transformation of Public Healthcare Organizations

Using a combination of institutional and dilemma theory, this article maps the core dilemmas underlying the transformation of three public healthcare organizations into municipal enterprises. The results concerning the expectations and outcomes of the processes of change show that identified dilemmas affect the isomorphic institutional process by either diminishing or enhancing isomorphic forces. Further analysis reveals the unconscious use of the dilemma reconciliation method among the senior managers and other decision-makers in the organizations. The discussion illustrates how dilemmas, together with isomorphic forces, are connected to decision-making. It highlights the need to investigate strategic dilemma management as a tool for resolving contradictory aims in the public healthcare sector.     

Venture Capital Syndication: Synthesis and future directions

This paper reviews and synthesizes the extant literature on venture capital syndication. By considering the questions of how, why and when syndication affects the performance of venture capitalist (VC) firms and their portfolio ventures, a schematic structure of the syndication literature is formed and areas for further research are identified. The results of the review show that, while the venture‐level aspects are relatively well understood, the current literature lacks an understanding of how and why syndication affects the performance of VC firms. This suggests that more attention should be directed towards syndication as a component of the overall strategy of VC firms.     

Scheduling with interjob communication on parallel processors

Consider a scheduling problem in which a set of tasks needs to be scheduled on m parallel processors. Each task \(T_i\) consists of a set of jobs with interjob communication demands, represented by a weighted, undirected graph \(G_i\). The processors are assumed to be interconnected by a shared communication channel, which can be used by jobs to communicate among each other while being processed in parallel. In each time step, the scheduler assigns jobs to the processors and allows any processed job to use a certain capacity of the channel in order to satisfy (parts of) its communication demands to adjacent jobs processed in the same step. The goal is to find a schedule with minimum length in which the communication demands of all jobs are satisfied. We show that this problem is NP-hard in the strong sense even if the number of processors is constant and the underlying graph is a single path or a forest with arbitrary constant maximum degree. Consequently, we design and analyze approximation algorithms with asymptotic approximation ratio \(\min \{1.8, 1.5 \frac{m}{m-1}\}+1\) if the underlying graph G, the union of the \(G_i\), is a forest. For general graphs it is \(\min \left\{ 1.8, \frac{1.5m}{m-1}\right\} \cdot \left( \text {arb}(G) + \frac{5}{3}\right) \), where \(\text {arb}(G)\) denotes the arboricity of G.     

Optimality conditions for a bilevel matroid problem

In bilevel programming there are two decision makers, the leader and the follower, who act in a hierarchy. In this paper we deal with a weighted matroid problem where each of the decision makers has a different set of weights. The independent set of the matroid that is chosen by the follower determines the payoff to both the leader and the follower according to their different weights. The leader can increase his payoff by changing the weights of the follower, thus influencing the follower’s decision, but he has to pay a penalty for this. We want to find an optimum strategy for the leader. This is a bilevel programming problem with continuous variables in the upper level and a parametric weighted matroid problem in the lower level. We analyze the structure of the lower level problem. We use this structure to develop local optimality criteria for the bilevel problem that can be verified in polynomial time.