Underpricing of energy IPOs in Australia

The underpricing of initial public offerings (IPOs) has been discussed in the literature for over thirty years. Underpricing is the term used when the issue price of the shares of a company raising public equity capital and seeking to list on a stock exchange is below the closing price of the shares on the first day of listing. As such, underpricing theoretically allows subscribing investors the opportunity of making a return on the day of listing. The international evidence as examined in [4] and updated in [5] has documented that subscribing investors made handsome double-digit' (for example US IPOs - 15.7%, UK IPOs 12%, Turkish IPOs - 13.1 %, Greek IPOs -49.0%) or even triple-digit (for example Chinese IPOs 256.9%) statistically significant positive first day returns, on average. These studies are generally however of industrial company IPOs.

The purpose of this paper is to investigate the underpricing returns of Australian energy IPOs from January 1994 to June 2007. Two previous studies into natural resource IPOs in Australia only made fleeting mention of energy IPOs because of the small sample sizes. [3] identified 2 solid fuel IPOs and 13 oil and gas IPOs (amongst 130 other natural resource IPOs) during 1979 to 1990 and advised average underpricing returns of 106.5% and 47.3% respectively for investors subscribing to these IPOs. [2] investigated 19 energy IPOs (amongst 96 other natural resource IPOs) from 1994 to 1999 and reported an average underpricing return of 8.3%.

The sample set of 134 used in this study is significantly greater than previous Australian studies. These 134 energy IPOs raised over $1.945 billion of public equity capital from January 1994 to June 2007. [3] reports on the importance of the natural resources sectors to Australia's economy and the fact that companies working in these sectors constitute around one third of the entities listed on the Australian Stock Exchange.

This study also follows a highly influential paper in the IPO literature by [I]. They argue that the lower the uncertainty about the value of an IPO, the lower the underpricing needed to attract subscribers. Given the linkage between uncertainty and underpricing, this study seeks to identify the factors that might influence uncertainty and hence underpricing.

The study found that the mean underpricing return for these energy lPOs is 22.8% and statistically significant. The model used to investigate variables that might help explain the level of underpricing in this industry sector is also particularly useful. An important finding in the study for new issuers, underwriters and subscribing investors is that those energy IPO firms that used underwriters had substantially lower underpricing. The other finding that larger issues are likely to have lower underpricing is consistent with prior industrial company IPO studies.

Associations of maternal long-chain polyunsaturated fatty acids, methyl mercury, and infant development in the Seychelles Child Development Nutrition Study

Fish consumption during gestation can provide the fetus with long-chain polyunsaturated fatty acids (LCPUFA) and other nutrients essential for growth and development of the brain. However, fish consumption also exposes the fetus to the neurotoxicant, methyl mercury (MeHg). We studied the association between these fetal exposures and early child development in the Seychelles Child Development Nutrition Study (SCDNS). Specifically, we examined a priori models of Ω-3 and Ω-6 LCPUFA measures in maternal serum to test the hypothesis that these LCPUFA families before or after adjusting for prenatal MeHg exposure would reveal associations with child development assessed by the BSID-II at ages 9 and 30 months. There were 229 children with complete outcome and covariate data available for analysis. At 9 months, the PDI was positively associated with total Ω-3 LCPUFA and negatively associated with the ratio of Ω-6/Ω-3 LCPUFA. These associations were stronger in models adjusted for prenatal MeHg exposure. Secondary models suggested that the MeHg effect at 9 months varied by the ratio of Ω-6/Ω-3 LCPUFA. There were no significant associations between LCPUFA measures and the PDI at 30 months. There were significant adverse associations, however, between prenatal MeHg and the 30-month PDI when the LCPUFA measures were included in the regression analysis. The BSID-II mental developmental index (MDI) was not associated with any exposure variable. These data support the potential importance to child development of prenatal availability of Ω-3 LCPUFA present in fish and of LCPUFA in the overall diet. Furthermore, they indicate that the beneficial effects of LCPUFA can obscure the determination of adverse effects of prenatal MeHg exposure in longitudinal observational studies.

Bipolar II disorder : a review

Objectives: To review the current knowledge of bipolar II disorder.

Methods: Literature was reviewed after conducting a Medline search and a hand search of relevant literature.

Results: Bipolar II disorder is a common disorder, with a prevalence of approximately 3–5%. Distinct clinical features of bipolar II disorder have been described. The key to diagnosis is the recognition of past hypomania, while depression is the typical presenting feature of the illness. This is responsible for a significant rate of missed diagnosis, and consequent management according to unipolar guidelines. It is unclear if bipolar II disorder is over-represented amongst resistant depression populations and if abrupt offset of antidepressant action is a phenomenon over represented in bipolar II disorder, reflecting induction of predominantly depressive cycling. A few mood-stabilizer studies available provide provisional suggestion of utility. A supportive role for psychosocial therapies is suggested, however, there is a sparsity of published studies specific to bipolar II disorder cohorts. A small number of short-term antidepressant trials have suggested efficacy, however, compelling long-term maintenance data is absent.

Conclusions: An emerging literature on the specific clinical signature and management of the disorder exists, however, this is disproportionately small relative to the epidemiology and clinical significance of the disorder.