Preventing HIV in injection drug users: exploring the tradeoffs between interventions

Injection drug users (IDUs) transmit the human immunodeficiency virus (HIV) via both needle sharing and sex. Available interventions for this population have varying costs and effectiveness and focus on different risk behaviors. In this analysis, we look at two interventions. One is inexpensive, broad-based and provides modest risk reductions (street outreach (SO)); the other is narrowly focused, expensive and relatively effective (methadone maintenance). This analysis explores the effects of population risk behavior, intervention effectiveness, intervention costs, and decision constraints when allocating funds between these two interventions to maximize effectiveness. We develop a model of the spread of HIV, dividing IDUs into susceptibles (uninfected) and infectives, and separately portraying sex and injection risk. We simulate the epidemic in New York City for time periods from the mid-1980s to the early 1990s, and incorporate the behavioral effects of two interventions performed singly or in combination to find the allocation that maximizes the number of infections averted in the IDUs and their noninjecting sex partners, assuming interventions have increasing marginal costs. We find that the optimal allocation nearly always involves spending the maximum allowable amount on SO. This result is largely insensitive to variations in risk parameters, intervention efficacy, or cost. The model's structure, however, makes clear that many factors contribute to this insensitivity, namely the scope of the interventions, the dual drug/sex nature of HIV risk in the population, the asymmetry of sexual risk for men and women, and the potential benefits to nonIDUs.     

Can the Timing of Negotiations Impact the Consequences of Mergers?

This paper uses a theoretical model to examine whether variation in the timing of negotiations between buyers and sellers can alter the effects of mergers between sellers. The model shows that mergers between horizontally overlapping firms lead to price increases regardless of how negotiations take place. In contrast, mergers between firms in different markets can only lead to higher compensation for the combined firm when negotiations occur sequentially. However, any price effects from out‐of‐market mergers stem from a mechanical redistribution of existing market power and not from a loss in competition. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.     

The impact of reporting frequency on the information quality of share price: evidence from Chinese state-owned enterprises

As a major global exchange, the Stock Exchange of Hong Kong (SEHK) only requires semi-annual reporting whereas other major exchanges including the ones in Chinese mainland require quarterly reporting. We argue against the traditional view that higher reporting frequency is necessarily more beneficial. The decision on reporting frequency depends on how the information is being processed by the recipient traders and the results are not obvious. Using a sample of Chinese companies duallisted in both China A share market and SEHK (AH shares) as the experimental group and mainland’s companies listed on SEHK (H shares) only as the control group, we apply the difference-in-difference (DID) method to investigate the impacts of reporting frequency on stock information quality. The results suggest that after China A share market require quarterly financial reporting for all listed companies in 2002, the information asymmetry of the H tranche of AH stocks increases. Different from prior studies, the results suggest a negative association between stock information quality and financial reporting frequency. We argue that the increased information asymmetry in the H tranche is caused by the noise spilled over from the A tranche. We conduct multivariable GARCH tests and find evidence supporting this conjecture.     

To What Extent do United Kingdom Companies Provide Oil and Gas Reserves Information Sufficient to Satisfy Statement of Recommended Practice Requirements?

The uncertainty surrounding oil and gas reserves estimation and the cost of gathering reserves data discourage firms from disclosing sufficient data to satisfy SORP (statement of recommended practice) requirements, especially where oil and gas reserves disclosure is discretionary. However, the need to reduce agency cost and signal to stakeholders induces firms to disclose oil and gas reserves. The contrasting views on the rationale guiding the extent of disclosure were examined in this study. A sample was drawn from 83 United Kingdom (UK) oil and gas exploration and production companies listed on the London Stock Exchange. Appropriate statistical tools were used to investigate the extent of oil and gas reserves disclosure. The findings provide mixed results about the extent of disclosure to meet SORP's requirements. There was no particular evidence that UK oil and gas companies provide qualitatively acceptable oil and gas reserves quantity information. The observed varying degrees of disclosure in the market could be attributed to a discretionary regime that allows firms to determine how and when to disclose. Policy makers and industry regulators could find the results useful in assessing the current extent of disclosure compliance.     

中国"以电子政务拉动信息产业发展"政策的再评估

电子政务是中国信息化战略的重中之重,但其实际发展与预期间存在着明显差距。本文以中国“以电子政务拉动信息产业发展”政策为研究重点,把这一政策放在中国信息化历史中加以考察,分析中国信息化新阶段ICT市场的新变化和新挑战,针对电子政务实践与预期间的差距,对该政策提出我们的看法。     

Valuing GM technologies using real options: the case of drought tolerant wheat in Australia

ABSTRACT

In this article we seek to estimate the value of a partially-developed crop technology from the perspective of the firm developing the technology. Firms need this value estimation to decide whether their technology will earn a sufficient return in the market to justify investing in it. However, determining the (ex-ante) value of the technology before it is commercialised is challenging as the technology is not yet in the market and hence the demand function has not yet been defined. An alternative valuation method is required. We use risk premiums, Monte Carlo simulation and real options analysis and we demonstrate this combination of valuation tools on wheat that is currently being developed in Australia to be drought tolerant. The results indicate that this drought tolerant wheat variety is likely to be adopted by farmers in most regions and has a pre-commercialisation value that justifies continued investment in its development. We also identified South Australia as a region in which the new variety would not be sufficiently valuable to farmers to see them adopt it and we consider possible explanations for this outcome.     

The Quality of Institutions and Organizational Form Decisions: Evidence from Within the Firm

In many retail and service sectors, firms have to establish a physical presence in a geographic market to access customers there. In countries where the quality of institutions is low, this can put assets at risk. We use data on the operations of a multinational, multibrand hotel company to show that in environments where local institutions are weaker—as proxied mainly by the World Bank's Checks index—the company eschews direct ownership. Rather than increasing its reliance on franchising, as predicted by some models, the company relies more on another form of organization commonly used in this industry, namely management contracts. We explain these patterns by emphasizing how the quality of the institutional environment affects the cost of using equity‐based organizational forms, per arguments in the current literature, but also the cost of enforcing the terms of franchise contracts.     

Multiperiod hedging in the presence of stochastic volatility

In this paper, we characterize the multiperiod minimum-risk hedge strategy within the stochastic volatility (SV) framework and compare it to other hedge strategies on the basis of hedging performance. Using crude oil markets as an example, we demonstrate that the SV model is appropriate in depicting price behaviour. However, ex ante and ex post comparisons indicate that the SV strategy is inferior to conventional hedging strategies. There is also evidence that the Generalized Autoregressive Conditional Heteroskedasticity (GARCH) strategy may be better than the SV strategy, at least in terms of variance reduction.