Bias of damage awards and free options in securities litigation

Damage measures in securities fraud cases are very imprecise because they are based on security price changes that reflect both the correction of previous misrepresentation and other independent information. Consequently, potential plaintiffs have a valuable “free option” to decide whether or not to file suit, and average damage awards are greater than actual damages, much greater when markets are volatile. The “Private Securities Litigation Reform Act of 1995” was intended to curb abusive litigation and to address the problem of excessive damage awards. Motivated by a misdiagnosis that excess awards are due to temporary price drops, the Act limits damages to the difference between the purchase price and the time-averaged trading price from the release of the corrective information until 90 days later or until the sale of the security, whichever is first. Unfortunately, the Act's modified measure of damages suffers from a more severe free-option problem than did the traditional measure. Also, the Act introduced an additional new option to time the sale of the security; the effects of these options may be mitigated by the impact of the positive drift in stock prices over time, if the time-averaged price is not adjusted for market movements. As a result, the bias can be larger or smaller under the new Act, depending on how severe the free-option problem is. We propose an alternative approach to addressing the issue of excessive damages: courts should adopt a threshold of measured damages below which no damage would be awarded. The threshold would depend on several factors, most notably the volatility of the stock in the period under question. That is, damages will be awarded only if measured damages exceed the threshold, and awards would be capped by the formula presented in the Reform Act.

Twisting the knife: discrimination in the law

Of the many different variations that can occur in human sexual formation, transsexualism no doubt remains the least understood by the wider Australian community. As a consequence, the process of attaining human rights to legal status, privacy, dignity and freedom from discrimination for those who experience this unusual condition has been a slow and sometimes frustrating one. The article seeks to introduce the reader to some of the more recent developments in the international jurisprudence of transsexualism and the underlying medical evidence that has supported them. It also offers criticism of the belated attempt by the State of Victoria,  with the Births, Deaths & Marriages Registration (Amendment) Act 2004, to establish certain statutory rights in this regard. While the legislation was enacted with the stated and very laudable purpose of providing for the  correction of birth records on the Register of Births of those people with transsexualism who have altered their phenotypic sex by hormonal  medication and surgery, the article argues it has also served to remove other equally important rights already won and proposes that a final remedy will only be found, as on previous occasions, in the courts.

Recommendations for improved data processing from expired gas analysis indirect calorimetry

There is currently no universally recommended and accepted method of data processing within the science of indirect calorimetry for either mixing chamber or breath-by-breath systems of expired gas analysis. Exercise physiologists were first surveyed to determine methods used to process oxygen consumption ([OV0312]O 2) data, and current attitudes to data processing within the science of indirect calorimetry. Breath-by-breath datasets obtained from indirect calorimetry during incremental exercise were then used to demonstrate the consequences of commonly used time, breath and digital filter post-acquisition data processing strategies. Assessment of the variability in breath-by-breath data was determined using multiple regression based on the independent variables ventilation (VE), and the expired gas fractions for oxygen and carbon dioxide, FEO 2 and FECO2, respectively. Based on the results of explanation of variance of the breath-by-breath [OV0312]O2 data, methods of processing to remove variability were proposed for time-averaged, breath-averaged and digital filter applications. Among exercise physiologists, the strategy used to remove the variability in sequential [OV0312]O2 measurements varied widely, and consisted of time averages (30 sec [38%], 60 sec [18%], 20 sec [11%], 15 sec [8%]), a moving average of five to 11 breaths (10%), and the middle five of seven breaths (7%). Most respondents indicated that they used multiple criteria to establish maximum [OV0312]O 2 ([OV0312]O2max) including: the attainment of age-predicted maximum heart rate (HRmax) [53%], respiratory exchange ratio (RER) >1.10 (49%) or RER >1.15 (27%) and a rating of perceived exertion (RPE) of >17, 18 or 19 (20%). The reasons stated for these strategies included their own beliefs (32%), what they were taught (26%), what they read in research articles (22%), tradition (13%) and the influence of their colleagues (7%). The combination of VE, FEO 2 and FECO2 removed 96-98% of [OV0312]O2 breath-by-breath variability in incremental and steady-state exercise [OV0312]O2 data sets, respectively. Correction of residual error in [OV0312]O2 datasets to 10% of the raw variability results from application of a 30-second time average, 15-breath running average, or a 0.04 Hz low cut-off digital filter. Thus, we recommend that once these data processing strategies are used, the peak or maximal value becomes the highest processed datapoint. Exercise physiologists need to agree on, and continually refine through empirical research, a consistent process for analysing data from indirect calorimetry.

Simulated astigmatism impairs academic-related performance in children

Purpose: Astigmatism is an important refractive condition in children. However, the functional impact of uncorrected astigmatism in this population is not well established, particularly with regard to academic performance. This study investigated the impact of simulated bilateral astigmatism on academic-related tasks before and after sustained near work in children. Methods: Twenty visually normal children (mean age: 10.8 ± 0.7 years; six males and 14 females) completed a range of standardised academic-related tests with and without 1.50 D of simulated bilateral astigmatism (with both academic-related tests and the visual condition administered in a randomised order). The simulated astigmatism was induced using a positive cylindrical lens while maintaining a plano spherical equivalent. Performance was assessed before and after 20 min of sustained near work, during two separate testing sessions. Academic-related measures included a standardised reading test (the Neale Analysis of Reading Ability), visual information processing tests (Coding and Symbol Search subtests from the Wechsler Intelligence Scale for Children) and a reading-related eye movement test (the Developmental Eye Movement test). Each participant was systematically assigned either with-the-rule (WTR, axis 180°) or against-the-rule (ATR, axis 90°) simulated astigmatism to evaluate the influence of axis orientation on any decrements in performance. Results: Reading, visual information processing and reading-related eye movement performance were all significantly impaired by both simulated bilateral astigmatism (p < 0.001) and sustained near work (p < 0.001), however, there was no significant interaction between these factors (p > 0.05). Simulated astigmatism led to a reduction of between 5% and 12% in performance across the academic-related outcome measures, but there was no significant effect of the axis (WTR or ATR) of astigmatism (p > 0.05). Conclusion: Simulated bilateral astigmatism impaired children's performance on a range of academic-related outcome measures irrespective of the orientation of the astigmatism. These findings have implications for the clinical management of non-amblyogenic levels of astigmatism in relation to academic performance in children. Correction of low to moderate levels of astigmatism may improve the functional performance of children in the classroom.

Neither fixed nor random: weighted least squares meta-regression

Our study revisits and challenges two core conventional meta-regression estimators: the prevalent use of‘mixed-effects’ or random-effects meta-regression analysis and the correction of standard errors that defines fixed-effects meta-regression analysis (FE-MRA). We show how and explain why an unrestricted weighted least squares MRA (WLS-MRA) estimator is superior to conventional random-effects (or mixed-effects) meta-regression when there is publication (or small-sample) bias that is as good as FE-MRA in all cases and better than fixed effects in most practical applications. Simulations and statistical theory show that WLS-MRA provides satisfactory estimates of meta-regression coefficients that are practically equivalent to mixed effects or random effects when there is no publication bias. When there is publication selection bias, WLS-MRA always has smaller bias than mixed effects or random effects. In practical applications, an unrestricted WLS meta-regression is likely to give practically equivalent or superior estimates to fixed-effects, random-effects, and mixed-effects meta-regression approaches. However, random-effects meta-regression remains viable and perhaps somewhat preferable if selection for statistical significance (publication bias) can be ruled out and when random, additive normal heterogeneity is known to directly affect the ‘true’ regression coefficient.