Stock market volatility is the systematic risk faced by investors who hold a market portfolio (e.g., a stock market index fund). Schwert (1989b) has undertaken an extensive study of stock market volatility, using historical data back to the 19th century. Some of his major findings are illustrated in Figure 1, which plots quarterly stock market volatility for the post-World War II period.1 The f...

OBJECTIVE To evaluate health facility and health worker readiness to deliver new artemether-lumefantrine (AL) treatment policy for uncomplicated malaria in Kenya. DESIGN Cross-sectional survey. SETTING Health facilities in four sentinel districts in Kenya. PARTICIPANTS All government facilities in study districts (n = 211) and all health workers performing outpatient consultations (n = 65...

OBJECTIVES Since 2004, the government of Tanzania has been rolling out antiretroviral treatment programs all over the country. However, the capacity of the health system to cope with the rapid scale-up of these programs is a major concern, and problems may result in drug stock-outs that force changes in treatment regimens. This study aims to explore stock-outs of antiretroviral drugs and furthe...

We propose a model-free omnibus statistical procedure to check whether the direction of changes in an economic variable is predictable using the history of its past changes. A class of separate inference procedures are also given to gauge possible sources of directional predictability. They can reveal information about whether the direction of future changes is predictable using the direction, ...

BACKGROUND To evaluate the type and frequency of antiretroviral drug stock-outs, and their impact on death and interruption in care among HIV-infected patients in Abidjan, Côte d'Ivoire. METHODS AND FINDINGS We conducted a cohort study of patients who initiated combination antiretroviral therapy (cART) in three adult HIV clinics between February 1, 2006 and June 1, 2007. Follow-up ended on Fe...

Study of various transportation indicators could be an appropriate criterion in evaluating the performance of the existing railways throughout the globe. This study was carried out to investigate the performance of rolling stock of Iranian railway using productivity analysis. In order to solve the problems, some solutions were provided by productivity management cycle steps. At the first step, ...

Soft computing methods and various sentiment indicators are employed to conduct out-of-sample predictions of the future sign of the stock market returns. In particular, we assess the performance of the probabilistic neural network (PNN) against the back-propagation neural network (BPNN) in predicting technology stocks and NYSE up and down moves. Genetic algorithms (GA) are employed to optimize ...

The authors examine the link between consumption and disaggregate wealth in Canada. They use a vector-error-correction model in which permanent and transitory shocks are identified using the restrictions implied by cointegration proposed by King, Plosser, Stock, and Watson (1991) and Gonzalo and Granger (1995). This procedure allows the authors to identify the reaction of consumption to both ty...

The goal of this study was to carry out singleand multi-aspect ABC analyses in spare parts warehouse. Two cases were considered within the investigations. First case concerned stock with the required safety stock, whereas in the second case, safety stock was neglected. Comparison of the results for both analyses was to show how the level of safety stock impacts on selection of more profitable a...