Another look at long memory in common stock returns

We apply the modified rescaled range test to the return series of 1,952 common stocks. The results indicate that long memory is not a widespread characteristic of these stocks. But logit models of the event of a test rejection reveal that rejections are linked to firms with large risk-adjusted average returns. The maximal moment of a return distribution is also found to influence the event of a rejection, but not in a way suggestive of moment-condition failure. Evidence suggestive of survivorship bias is also uncovered. We conclude that there is some evidence consistent with persistent long memory in the returns of a small proportion of stocks.     

Long term dependence in stock returns

We show, using the modified rescaled range statistic, that none of the return series of indices of five European countries, the United States and Japan exhibits long term dependence. This statistic — introduced by Lo (1991) — correct Hurst's (1951) ‘classical’ rescaled range statistic for short term dependence. We also report the classical rescaled range statistic after adjusting the series for short term dependence. This procedure shows, for cases where the results of the modified rescaled range statistic are mixed, that no long term dependence can be found. Simulations indicate reasonable power of this adjustment procedure. Furthermore, we find that estimates of the Hurst exponent, a related measure of long term dependence, are also biased by short term dependence. Simulations show that this measure — that has recently attracted growing interest — cannot distinguish between models with or without long term dependence.     

The Friday Effect in European Securitized Real Estate Index Returns

This study extends research on the day-of-the-week effect towards European real estate indices. We examine this anomaly for several European securitized real estate index returns between 1990 and 2003. Although the countries under analysis have unique country-specific patterns, we find that eight out of eleven European countries exhibit abnormally high Friday returns. Moreover, two different Europe indices also exhibit the Friday anomaly. The anomaly is robust with respect to extreme observations, alternative specifications and several well-known calendar effects.     

A study of earnings-management motives in the Anglo-American and Euro-Continental accounting models: The Canadian and French cases

The purpose of this paper is to investigate factors that potentially influence earnings-management policy with reference to the Anglo-American and Euro-Continental accounting models. Canada and France, respectively, belong to those different socio-economic environments. Earnings-management practices detected in those countries are expected to be affected by specific socio-economic features of the Anglo-American and the Euro-Continental environments. We explain earnings-management practices by incentives suggested in the literature to reveal which motives are prominent within each environment.We tested our earnings-management motives (EMM) model using appropriate panel-estimation techniques over 1674 Canadian and 1470 French firm-year observations. Our results provide evidence that incentives for earnings management for French firms are specifically linked to contractual debt costs and effective tax rate. However, Canadian firms show specific incentives matched with a dynamic capital market. Issuing equity is a strong motive for earnings management in Canadian firms.     

Mean–variance and mean–semivariance portfolio selection: a multivariate nonparametric approach

While univariate nonparametric estimation methods have been developed for estimating returns in mean-downside risk portfolio optimization, the problem of handling possible cross-correlations in a vector of asset returns has not been addressed in portfolio selection. We present a novel multivariate nonparametric portfolio optimization procedure using kernel-based estimators of the conditional mean and the conditional median. The method accounts for the covariance structure information from the full set of returns. We also provide two computational algorithms to implement the estimators. Via the analysis of 24 French stock market returns, we evaluate the in-sample and out-of-sample performance of both portfolio selection algorithms against optimal portfolios selected by classical and univariate nonparametric methods for three highly different time periods and different levels of expected return. By allowing for cross-correlations among returns, our results suggest that the proposed multivariate nonparametric method is a useful extension of standard univariate nonparametric portfolio selection approaches.     

Healthcare costs of stroke and major bleeding in patients with atrial fibrillation treated with non-vitamin K antagonist oral anticoagulants

Objective: To assess long-term healthcare costs related to ischemic stroke and systemic embolism (stroke/SE) and major bleeding (MB) events in patients with non-valvular atrial fibrillation (NVAF) treated with non-vitamin K antagonist oral anticoagulants (NOACs).

Materials and methods: Optum’s Clinformatics Data Mart database from 1/2009–12/2016 was analyzed. Adult patients with ≥1 stroke/SE hospitalization (index date) were matched 1:1 to patients without stroke/SE (random index date), based on propensity scores. Patients with an MB event were matched to patients without MB. All patients had an NOAC dispensing overlapping index date, ≥12?months of eligibility pre-index date, and ≥1 NVAF diagnosis. The observation period spanned from the index date until the earliest date of death, switch to warfarin, end of insurance coverage, or end of data availability. Mean costs were evaluated: (1) per-patient-per-year (PPPY) and (2) at 1, 2, 3, and 4?years using Lin's method.

Results: The cost differences were, respectively, $48,807 and $28,298 PPPY for NOAC users with stroke/SE (n?=?1,340) and those with MB (n?=?3,774) events compared to controls. Cost differences of patients with vs without stroke/SE were $49,876, $51,627, $57,822, and $60,691 at 1, 2, 3, and 4?years post-index, respectively (p?p?Limitations: Limitations include unobserved confounders, coding and/or billing inaccuracies, limited sample sizes over longer follow-up, and the under-reporting of mortality for deaths occurring after 2011.

Conclusions: The incremental healthcare costs incurred by patients with vs without stroke/SE was nearly twice as high as those of patients with vs without MB. Moreover, each additional year up to 4?years after the first event was associated with an incremental cost for patients with a stroke/SE or MB event compared to those without an event.     

Demand for,and impediments to,the disclosure of information about climate change-related corporate governance practices

Based on a survey of climate change experts in different stakeholder groups and interviews with corporate climate change managers, this study provides insights into the gap between what information stakeholders expect, and what Australian corporations disclose. This paper focuses on annual reports and sustainability reports with specific reference to the disclosure of climate change-related corporate governance practices. The findings culminate in the refinement of a best practice index for the disclosure of climate change-related corporate governance practises. Interview results indicate that the low levels of disclosures made by Australian companies may be due to a number of factors. A lack of proactive stakeholder engagement and an apparent preoccupation with financial performance and advancing shareholders interest, coupled with a failure by managers to accept accountability, seems to go a long way to explaining low levels of disclosure.     

Managerial Commitment to Sustainable Supply Chain Management Projects

Most companies are under pressure to improve the environmental sustainability of their supply chains. However, there is considerable variance in companies' ability to successfully deploy environmental management projects. One important factor, according to articles in the academic and business press, is the ability of champions of sustainable supply chain management (SCM) projects within organizations to gain the commitment of colleagues (e.g., other managers from a variety of functions) to help these projects succeed. Therefore, this paper examines variables that affect a project champion's ability to gain this commitment from colleagues. In particular, building on existing research, this research employs a video‐based experimental design to examine the effect of the influence approach that the project champion employs, the values of the person the champion is trying to influence, and the organizational climate. The results suggest that organizational climate and certain individual values directly affect commitment. There are also interactions between values and influence tactics. The research adds to the field's growing knowledge on the antecedents of sustainable SCM within companies while providing valuable guidance for environmental champions and for top managers.     

Reversible Environmental Catastrophes with Disconnected Generations

De Economist - We study environmental policy in a stylized economy–ecology model featuring multiple deterministic stable steady-state ecological equilibria. The economy–ecology does not...