Grazing into the future: Policy making for South African communal rangelands

This article reports on a symposium held at Fort Hare University in July 1998. Its objective was to assess the current state of knowledge on communal rangelands and identify issues important for policy making. This was done in the light of concerns about recent policy reform. Uncontrolled access to resources and the lack of services were identified as the main constraints on socio‐economic development in the communal rangelands, and inadequate forage during the dry season was recognised as a general constraint on livestock production, irrespective of mean annual rainfall. Government policies must recognise these issues and the social and ecological heterogeneity of communal rangelands in South Africa. The conclusion with the most far‐reaching implications, however, was that degradation has occurred in some, but not all, communal rangelands and is most likely to occur in arid areas. This finding is in direct contrast to the current base for agricultural policies in South Africa, which assumes that livestock have little impact on rangelands.     

Replication in strategic management: scientific testing for validity,generalizability, and usefulness

A number of studies have shown that little replication and extension research is published in the business disciplines. This has deleterious consequences for the development of a cumulative body of knowledge in these same areas. It has been speculated, but never formally tested, that replication research is more likely to be published in lower tiers of the journal hierarchy. The present paper indicates very low levels of replication in management and strategic management journals, regardless of their prestige. Moreover, even those replications that are published tend not to be critical—odd in applied social sciences that are largely preparadigmatic and where extensibility, generalizability and utility of scientific constructs tend to be low. The goal of science is empirical generalization, or knowledge development. Systematically conducted replications with extensions facilitate this goal. It is clear, however, that many editors, reviewers, and researchers hold attitudes toward replication research that betray a lack of understanding about its role. Long-run strategies to dispel these misconceptions must involve changes in graduate training aimed at making the conduct of such vital work second nature. It is further suggested that journals in all tiers create a section specifically for the publication of replication research, and that top-tier journals take the lead in this regard. © 1998 John Wiley & Sons, Ltd.     

Laws of large numbers for Hayashi–Yoshida-type functionals

The main object in the statistical analysis of high-frequency financial data are sums of functionals of increments of stochastic processes, and statistical inference is based on the asymptotic behaviour of these sums as the mesh of the observation times tends to zero. Inspired by the famous Hayashi–Yoshida estimator for the quadratic covariation based on two asynchronously observed stochastic processes, we investigate similar sums for general functionals. We find that our results differ from corresponding results for synchronous observations, a case which has been well studied in the literature, and we observe that the asymptotic behaviour in the setting of asynchronous observations is not only determined by the nature of the functional, but also depends crucially on the asymptotics of the observation scheme. Several examples are discussed, including the case of \(f(x_{1},x_{2}) = |x_{1}|^{p_{1}} |x_{2}|^{p_{2}}\) which has various applications in empirical finance.

     

Delegation and Incentives under Evolutionarily Stable Conjectures

Existing results show that in a homogenous Cournot duopoly, commitment by delegation harms profit. This conclusion presupposes that market conduct is the same whether incentives are aggressive or accommodating. We study delegation and incentives under evolutionarily stable conjectures and show how performance pay co‐determines market conduct. In fact, in equilibrium with evolutionarily stable conjectures, we show that commitment through delegation leads to a profit increase. Manipulation of managerial incentives produces less competition and therefore benefits firms' owners even in symmetric homogenous oligopoly. Copyright © 2016 John Wiley & Sons, Ltd.     

Gender Diversity in the Boardroom and Firm Performance: What Exactly Constitutes a “Critical Mass?”

The under-representation of women on boards is a heavily discussed topic—not only in Germany. Based on critical mass theory and with the help of a hand-collected panel dataset of 151 listed German firms for the years 2000–2005, we explore whether the link between gender diversity and firm performance follows a U-shape. Controlling for reversed causality, we find evidence for gender diversity to at first negatively affect firm performance and—only after a “critical mass” of about 30 % women has been reached—to be associated with higher firm performance than completely male boards. Given our sample firms, the critical mass of 30 % women translates into an absolute number of about three women on the board and hence supports recent studies on a corresponding “magic number” of women in the boardroom.     

Incentive pay and rent in oligopoly

Our purpose is to examine strategic delegation in nonlinear Cournot oligopoly. The findings generalize earlier results and show that managerial contracts reward sales under the condition of a fixed input price. Alternatively, under a variable input price, owners might punish sales even when goods are strategic substitutes. We conclude that optimal strategic motivation depends critically on the input price. For example, motivation that supports positive owner profit under a fixed input price nullifies owner-profit if an upstream monopolist with convex costs sets the input price. In a vertical relationship between a duopoly and an upstream monopolist, strategic delegation punishes sales.     

Bias-correcting the realized range-based variance in the presence of market microstructure noise

Market microstructure noise is a challenge to high-frequency based estimation of the integrated variance, because the noise accumulates with the sampling frequency. This has led to widespread use of constructing the realized variance, a sum of squared intraday returns, from sparsely sampled data, for example 5- or 15-minute returns. In this paper, we analyze the impact of microstructure noise on the realized range-based variance and propose a bias correction to the range-statistic. The new estimator is shown to be consistent for the integrated variance and asymptotically mixed Gaussian under simple forms of microstructure noise. We can select an optimal partition of the high-frequency data in order to minimize its asymptotic conditional variance. The finite sample properties of our estimator are studied with Monte Carlo simulations and we implement it using Microsoft high-frequency data from TAQ. We find that a bias-corrected range-statistic often leads to much smaller confidence intervals for the integrated variance, relative to the realized variance. We should like to thank an anonymous referee and the associate editor for insightful comments on an earlier draft. Parts of this paper were written while Kim Christensen was at the University of California, San Diego, whose hospitality is gratefully acknowledged. Mark Podolskij received financial support from CREATES funded by the Danish National Research Foundation, and Mathias Vetter was supported by the Deutsche Forschungsgemeinschaft grant SFB 475 “Reduction of Complexity in Multivariate Data Structures.” The code for this paper was written in the Ox programming language, due to Doornik (2002). All views expressed here are those of the authors and do not necessarily represent the views of Nordea.     

Consumption taxes in monopolistic competition: a comment

We show that an ad valorem tax is better than an equal-revenue unit tax when consumers spend some fixed proportion of income on taxed goods, when firms use constant mark-up pricing, and entry and exit drive per-firm profit to zero. These key assumptions implies that ad valorem taxes are superior in oligopoly as well as monopolistic competition, showing that earlier results on taxes in monopolistic competition (Schröder in J Econ 83(3):281–292, 2004) are not due to the mode of competition, but rather are due to the functional forms used.     

An alternative model for the analysis of variance with random effects

The standard model for the analysis of variance with random effects implies, for the case of two independent variables, that single effects must be tested not against the error, but against the interaction mean squares. This causes, in comparison with the fixed effects AV, a considerable loss of test power, particularly for the 2 × 2 table. An alternative modelling of the interaction effect is proposed which completely avoids the loss of power.