Portfolio selection in thinly traded environments—a case study

This paper proposes a flexible technique for selecting portfolios in an environment which includes thinly traded shares. The proposal uses the Capital Asset Pricing Model with a thinly traded beta estimator to generate the expected return input. This technique has the advantage of being applicable when the opportunity set includes well-traded securities, as the beta estimator converges to the ordinary least squares beta for well traded shares. In addition, it allows portfolio estimation to be carried out under a range of expected market performance scenarios. An empirical study on the Johannesburg Stock Exchange over the period 1974–85 indicates that the proposed method is superior to traditional techniques.     

Party realignments and the growth of federal economic regulation, 1861–1986

This article explains when and why the federal government passed laws with the intended goal of maintaining or improving a particular industry or segment of an industry. The adoption of regulatory laws across time will be described, and the surges and declines in the distribution explained. The empirical analysis covers the years 1861–1986.This article is an abbreviated version of a paper prepared for the 1988 Conference Perspectives on Banking Regulation, Federal Reserve Bank of Cleveland, November 3–4, 1988. I am very indebted to George J. Benston who allowed me to revise the paper in response to his criticisms.     

Population growth and the pattern of trade: A Neo-Ricardian approach

If the young and old provide economically distinct factors of production then the rate of growth of the population determines the factor endowment ratios and therefore both the composition of output and the pattern of foreign trade.     

Effective ways to grow urban bus markets – a synthesis of evidence

This paper provides a synthesis of the evidence on the patronage growth performance of bus improvement measures in urban settings. The evidence includes a summary of experience in Europe, North America and Australasia focusing on service improvement measures including network structure and service levels, bus priority measures, vehicles and stop infrastructure, fares and ticketing systems, passenger information and marketing, personal safety and security and synergy effects of measures. The source is the research literature and documented experienced from a series of studies undertaken by the authors over the last decade. It includes the results of an international bus expert ‘Delphi’ survey concerning bus improvement measures focussed on patronage growth. The paper synthesises the evidence to identify measures which are most likely to grow patronage including consideration of cost-effectiveness of measures.     

Healthcare resource utilization by patients with treatment-refractory myasthenia gravis in England

Aims: To examine healthcare resource utilization associated with refractory myasthenia gravis (MG) in England.

Materials and methods: This was a retrospective cohort study of linked data from the Clinical Practice Research Datalink and the Hospital Episode Statistics database collected between 1997 and 2016. Included patients were ≥18?years of age at the index MG diagnosis. Patients with refractory MG were identified using an algorithm based on treatments received. Healthcare resource utilization since the index date was compared between refractory and non-refractory cohorts.

Results: The study included 1149 patients with MG, of whom 66 (5.7%) were refractory. Sex and age at diagnosis did not significantly differ between the refractory and non-refractory cohorts. Rates of healthcare resource utilization per person-year were significantly higher (p?p?Limitations: The algorithm for identifying refractory patients did not include clinical criteria. Also, treatments administered in hospitals or by specialists were not available in the databases.

Conclusions: Patients in England with refractory MG more often visit healthcare providers, are hospitalized and visit an emergency room than patients with non-refractory MG.     

Biofuels technology development in Southern Africa

ABSTRACT

The benefits of biofuels depend on the feedstock, conversion pathway and local context. This paper assesses biofuels technology readiness and developments to provide foresight to biofuels development in Southern Africa. Efficient conversion pathways, coupled with biomass from waste or high-yielding energy crops, will reduce both the costs of biofuels production, and the environmental impacts. Compared to petroleum fuels, the current commercial biofuels (ethanol, biogas and biodiesel) typically offer carbon emission reductions of 30–50% but are marginally more expensive. The extent of biofuels market penetration will therefore be influenced by mandates (blending targets) and subsidies (green premium). Advanced biofuels promise greater efficiencies and carbon emission reductions at reduced cost but will require further research and development to reach commercialisation. If developed appropriately, biofuels can reduce carbon emissions and improve energy security, while enabling sustainable agriculture and improved natural resources management.