INNOVATION AND GROWTH WITH RICH AND POOR CONSUMERS

This work studies the impact of income inequality on the level of innovative activities in a model where innovations result in quality improvements. In contrast to the standard model of innovations and growth, the equilibrium outcome may be characterized by a situation where not only the quality leader but also producers of worse qualities are on the market. In that case the quality leader sells to the rich, whereas the producer of the second‐best quality sells to the poor. In general, we find that a more equal distribution of income is favourable for innovation incentives. This is consistent with empirical evidence suggesting that countries with a more equal distribution of income have grown faster.     

A Probabilistic Clustering Model for Variables of Mixed Type

This paper develops a probabilistic clustering model for mixeddata. The model allows analysis of variables of mixed type: thevariables may be nominal, ordinal and/or quantitative. The modelcontains the well-known models of latent class analysis as submodels.As in latent class analysis, local independence of the variables isassumed. The parameters of the model are estimated by the EMalgorithm. Test statistics and goodness-of-fit measures are proposedfor model selection. Two artificial data sets show the usefulness ofthese tests. An empirical example completes the presentation.     

The Austrian current account deficit: Driven by twin deficits or by intertemporal expenditure allocation?

The evidence presented in the paper rejects the twin deficit hypothesis for the Austrian current account balance during the last two decades. The results are based on an estimate of a vector error correction model including quarterly data for the current account balance and potentially relevant variables driving its dynamics. We compute the variance decomposition of the current account's forecast error and its generalized impulse responses to shocks in the innovations of the system. The results in favor of intertemporal expenditure reallocation cannot be reproduced within a second analysis including the current account and a measure of net output, however. The estimated implicit current account balance, interpreted as the discounted expected change in future net output, does not follow the actual behaviour of the current account. First version received: June 1999/Final version received: March 2001     

Modelling the impact of the ‘fast track’ land reform policy on Zimbabwe's maize sector

Zimbabwe has recently gone through a widely criticised land reform process that is argued to be the cause of subdued agricultural production. This paper attempts to present a counterfactual picture of the maize market in Zimbabwe had land reform been managed appropriately. The counterfactual is developed through a partial equilibrium framework in order to quantify the impact of the land reform programme. This, to our knowledge, is the first attempt at applying a partial equilibrium framework to an analysis of the impact of land reform. The results of the post-2000 land reform policy simulation showed that actual total maize output was lower than what could have been produced if it was under a pre-2000 land reform system. The study validates the assertion that land reforms contributed to the contraction of output. These results suggest the need for a well planned and executed land reform process, which can still play an important role in output growth and food security.     

International responses to homelessness: Lessons for the City of Tshwane

ABSTRACT

Reports of increases in the numbers of homeless people are pouring in from all over the world yet many governments still do not consider homelessness worthy of a policy response in its own right and relegate it to the periphery of either housing or social (welfare) policy arenas and interventions. In the introductory sections of this article, reference is made to the current extent of homelessness in the world and the rise to prominence of a rights-based approach to homelessness. This is followed by a brief overview of responses to homelessness in Australia, the USA and some European countries. A few of the key components of these responses and their relevance for homelessness policies in South Africa and the City of Tshwane are identified.     

Media-Based Sentiment Indices as an Alternative Measure of Consumer Confidence

In this paper, we consider the feasibility of constructing online sentiment indices, using large amounts of media data, as an alternative to the conventional survey method used to create the consumer confidence index in South Africa. A clustering framework is adopted to provide an indication of possible candidate sentiment indices constructed from a combination of different text sources and dictionaries that best mimic the traditional survey-based consumer confidence index from the South African Bureau for Economic Research (BER). The results conclude that it is possible to create an index using sentiment analysis using online editorial data that does resemble the BER’s consumer confidence index. The different media-based sentiment indices (MSI) show a significant level of correlation and co-movement with the BER’s CCI. Impulse responses and cross-correlation functions indicate that the MSI could potentially lead the survey-based method up to two quarters. Furthermore, Granger-causality tests show that the media-based indices are good predictors of future consumer confidence index values. The results provide motivation for further study on the use of sentiment-based techniques and online media data sources to track consumer confidence within an emerging market such as South Africa.     

Tests und Konfidenzintervalle für exponentielle Verteilungen und deren Anwendung auf einige diskrete Verteilungen

Zusammenfassung Es werden Verteilungen betrachtet, die (bezüglich irgendeines Ma?es) eine Dichte der GestaltC(ϑ) exp [ϑ x] besitzen. Für solche Verteilungen werden (ein- und zweiseitige) Tests und Konfidenzintervalle mit gewissen Optimalit?tseigenschaften entwickelt, und zwar fürϑ, für die Differenzϑ ₁ −ϑ ₂, sowie für einige Versionen desk-Stichproben Problems. Sodann werden einige Hilfss?tze über den bedingten Erwartungswert und die bedingte Varianz von zweiparametrigen Verteilungen abgeleitet, die bezüglich des einen Parameters reproduktiv sind und eine bezüglich des zweiten Parameters ersch?pfende und vollst?ndige Funktion besitzen. Schlie?lich werden die allgemeinen Ergebnisse auf einige diskrete Verteilungen (Binomial, Poisson, negativ Binomial, Pascal) angewendet und der Zusammenhang mit verschiedenen bekannten Tests diskutiert.

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Summary Probability distributions are considered which (with respect to any measure) possess a density function of the typeC(ϑ) exp [ϑ x]. For distributions of this type (one and twosided) tests and confidence intervals with some optimal properties are given, namely forϑ, for the differenceϑ ₁ −ϑ ₂, and for several versions of thek-sample problem. Furthermore, some lemmas concerning the conditional expectation and the conditional variance are proved for two-parameter families of distributions which are reproductive in one parameter and possess a complete statistic, sufficient for the second parameter. Finally the general results are applied to some discrete distributions (binomial, Poisson, negative binomial, Pascal) and the relationship to several fairly known tests is discussed.

     

Leveraging Green IS in Logistics

Logistics and especially road transportation account for a major proportion of global greenhouse gas emissions. Thus, increasing eco-sustainability is particularly important in this sector. Green information systems can support the transition towards more eco-sustainable business processes in logistics. To date research in Green IS has been dominated by conceptual and empirical studies, while the community has been reluctant to do design science research developing IS artifacts. Addressing this gap, we develop and evaluate a Green IS artifact for GHG emission tracking in road transportation processes – named Carbon Tracker. The design process was guided by design principles derived from prior Green IS literature. The artifact enables more eco-sustainable practices in logistics to emerge as it provides detailed information about GHG emissions that is indispensable for advanced organizational sense- and decision-making. The evaluation shows that the use of Carbon Tracker leads to more accurate and detailed information on emissions as well as more seamless and efficient workflows than today’s best-practice approaches. Thus, the paper demonstrates how Green IS can be leveraged for more eco-sustainable and efficient business processes and paves the way for further design-oriented research in the Green IS domain.