Antitrust Issues in Defining the Product Market for Hospital Services

In this paper we examine the standard product market relied on by the courts and antitrust agencies in hospital mergers-acute care, inpatient services-and consider whether narrower or broader alternatives may be more appropriate to assess the competitive effects of a hospital merger. To examine how much disaggregation of the standard product market definition may matter for the definition of relevant geographic markets and concentration, we considered patient flows and concentration for the overall inpatient 'cluster' and more disaggregated categories of service for two regions of California: San Luis Obispo and Sacramento. We find that a disaggregated approach may involve a relatively small number of inpatient service categories, that the overall cluster masked some variability in the underlying patient flows by service category, and that in San Luis Obispo, the overall cluster masked considerable detail in concentration at the service category level, which appeared to have been much less true in Sacramento.     

The 2004 Sumatra earthquake and Indian Ocean tsunami: What happened and why?

The December 26, 2004 Sumatra earthquake and the tsunami that followed killed over 300,000 people. In this paper, we analyze and discuss the geologic causes for this earthquake, the mechanisms that generated it, and follow up with a discussion on ways to prevent this type of disaster in the future.     

艾叶粗提物的分离提取及其抗肝癌活性组分筛选

为筛选艾叶水提物的抗肝癌活性组分,采用去溶剂和乙醇沉淀法,从等量的艾叶水提液中获得总水提物以及去多糖提取物和多糖提取物2种粗提物,用等量的去离子水溶解各提取物制成溶液,分别以不同的浓度作用HepG2细胞,倒置显微镜观察细胞的生长状态,MTT法测定细胞活力。结果为:处理肝癌细胞24~48h,不同浓度的总水提物和去多糖水提物能使肝癌细胞明显皱缩,OD值较对照组明显减小(P0.01),细胞最终死亡;而低、中浓度的多糖提取物对肝癌细胞的形态无明显影响,OD值较对照组小,但无统计学差异,高浓度的多糖提取物能使肝癌细胞明显皱缩,OD值较对照组小,有差异(P0.05)。去多糖水提物和总水提物的活性较强,能使肝癌细胞明显皱缩,阻滞其增殖,最终诱导死亡,多糖提取物作用较弱,能抑制肝癌细胞增殖。因此,进一步筛选抗癌活性精细组分或先导化合物可从艾叶去多糖水提物中深入研究。     

Capital Gains Taxes and Stockholders' Response to Dutch Auction Tender Offers

Capital gains taxes are conjectured to explain upward sloping supply curves in tender offers. This paper analyzes expiration day returns in Dutch auction tender offers to examine this conjecture. A proxy measure for the capital gains of the marginal tendering stockholder is constructed, based on tender offer size and daily price-volume history for one year. Cross-sectional regressions suggest that the tender price increases with the capital gains of the marginal tenderer, but only for firms with low institutional holdings. This is consistent with capital gains tax effects being relevant only when tax-exempt holdings are low.     

Is Occupational Injury Risk Higher at New Firms?*

This paper studies whether newly created firms have higher injury rates than established firms. We use data on a large sample of single‐establishment firms in Pennsylvania from 2001–2005 to examine the relationship between firm age and the risk of lost workday injuries. Using the full set of firms, there appears to be little overall correlation between firm age and risk. If anything, newer firms appear less likely to have lost workday injuries. When we condition on having at least one injury reported in 2000, however, we find that in later years the injury risk of firms declines with age. This pattern is consistent with systematic underreporting of injuries by new firms.     

Do Poorly Governed Acquirers Transfer Wealth to Targets in Cross‐Border Acquisitions?

We use the number of antitakeover provisions (ATPs) as a proxy for corporate governance and examine its impact in US domestic and foreign acquisitions made by US acquirers. We find that the targets of poorly governed acquirers earn higher postannouncement premiums, despite controls for deal characteristics, macroeconomic conditions, and country‐level protections, suggesting that these acquirers overpay. Puzzlingly, in contrast with the domestic US findings of Masulis, Wang, and Xie, poorly governed acquirers in cross‐border deals experience higher announcement period returns. The relation between governance and target returns appears concave, but this nonlinearity disappears once differences in country‐level governance and deal characteristics are accounted for.     

The elusive relation between pension discount rates and deficits

The relation between defined-benefit (DB) pension discount rates and funding status is more complex than it might first appear. Existing evidence suffers from estimation biases that make precise inference unreliable. We document the biases and quantify their impact on inference in relation to corporate window-dressing of DB funding status. Our empirical evidence from the United Kingdom suggests that pension sponsors use discretion in the choice of pension discount rate not only to reduce reported deficits but also to reduce reported surpluses.