Learning minimum variance discrete hedging directly from the market

Option hedging is a critical risk management problem in finance. In the Black–Scholes model, it has been recognized that computing a hedging position from the sensitivity of the calibrated model option value function is inadequate in minimizing variance of the option hedge risk, as it fails to capture the model parameter dependence on the underlying price (see e.g. Coleman et al., J. Risk, 2001, 5(6), 63–89; Hull and White, J. Bank. Finance, 2017, 82, 180–190). In this paper, we demonstrate that this issue can exist generally when determining hedging position from the sensitivity of the option function, either calibrated from a parametric model from current option prices or estimated nonparametricaly from historical option prices. Consequently, the sensitivity of the estimated model option function typically does not minimize variance of the hedge risk, even instantaneously. We propose a data-driven approach to directly learn a hedging function from the market data by minimizing variance of the local hedge risk. Using the S&P 500 index daily option data for more than a decade ending in August 2015, we show that the proposed method outperforms the parametric minimum variance hedging method proposed in Hull and White [J. Bank. Finance, 2017, 82, 180–190], as well as minimum variance hedging corrective techniques based on stochastic volatility or local volatility models. Furthermore, we show that the proposed approach achieves significant gain over the implied BS delta hedging for weekly and monthly hedging.     

From standard to evolutionary finance: a literature survey

Management Review Quarterly - The traditional financial paradigm seeks to understand financial markets by using models in which markets are perfect, which includes agents who are...     

Healthcare burden and reimbursement of hospitalization during chemotherapy for adults with Ph-negative relapsed or refractory B-cell precursor acute lymphoblastic leukemia in France: a retrospective chart review

Objective: Philadelphia chromosome negative [Ph(?)] relapsed or refractory (R/R) B-precursor acute lymphoblastic leukemia (ALL) is an extremely rare condition requiring intensive treatment. This retrospective chart review aimed to quantify hospitalizations and reimbursement in this patient population in France.

Methods: Patients aged ≥18 years and with at least one hospitalization for Ph(?) R/R B-precursor ALL were included in the study. They were relapsed with first remission lasting <12 months, relapsed after first salvage therapy, relapsed any time after hematopoietic stem cell transplant (HSCT), or were refractory to initial or salvage therapy. Data were collected from the index date (first diagnosis of R/R ALL) until death or loss to follow-up. The chemotherapy period was defined as the first chemotherapy date after the index date to the earliest of death, loss to follow-up, last chemotherapy dose plus 30 days, or initiation of HSCT. The primary outcome was the percentage of time hospitalized during the chemotherapy period.

Results: Thirty-three patients were included, with a mean age of 49 years. The mean proportion of time spent in the hospital during the chemotherapy period was 46% (95% CI =34–57%). Patients had a mean of 2.2 (SD =1.5) inpatient hospitalizations and the mean length of stay per hospitalization was 16.8 (SD =14.8) days. During the chemotherapy period, the mean amount reimbursed per hospitalization was €31 067 (SD = €4850) and the total hospitalization reimbursement per patient was €68 344. From the index date to death, excluding HSCT, the total reimbursement per patient was €108 873.

Limitations: The sample size was small, although this was expected given the rarity of the patient population.

Conclusions: Adults with Ph(?) R/R B-precursor ALL had repeated and prolonged hospitalizations during salvage chemotherapy. Approximately half the follow-up period was spent in the hospital, and this time was associated with high economic burden in France.     

Up in smoke: demarketing and consumer smoking cessation

The concept of demarketing refers to the use of marketing techniques to reduce or eliminate demand for a product or service. A review of the demarketing literature relating to health and specifically antismoking initiatives indicated that, while research on this topic exists, much of it is not grounded in an acceptable attitudinal or behavioural theory. After determining the importance placed by a sample of 18–24‐year olds on nine demarketing initiatives, two dimensions were identified that best explained this construct. Items within these dimensions were summed and averaged to form single variables, which were then used to form the attitudinal component of the Model of Goal Directed Behaviour. The findings showed that two of these variables – one that captured product packaging aspects and another that consisted of place and price items – significantly influenced the desire to quit and indirectly influenced the intention to quit. Anticipated positive emotions, frequency of quitting attempts and perceived control over quitting also positively influenced the desire and/or intention to quit. The article concludes with a discussion that interprets these findings from a theoretical and practical perspective and suggests directions for future research.     

Tax avoidance and ex ante cost of capital

This study examines the association between tax avoidance and ex ante cost of equity capital. Based on prior research, we develop two proxies for investors’ expectations of tax avoidance and explore whether deviations from those expectations result in higher ex ante cost of equity capital. We find that the ex ante cost of equity capital increases with tax avoidance that is either below or above investor expectations and that the increase is larger for tax avoidance that exceeds investors’ expectations. We then examine whether firms that alter their future tax avoidance exhibit a lowering of their ex ante cost of equity capital and find that tax avoidance decreases (increases) from the prior year for firms that were above (below) investors’ expectations in the prior year. These results are consistent with the trade‐off suggested by the Scholes and Wolfson framework and reinforce the notion that balancing tax benefits and non‐tax costs is an important feature of firms’ tax planning.     

SALES,INVENTORIES AND REAL INTEREST RATES: A CENTURY OF STYLIZED FACTS

We use Bayesian time‐varying parameter structural vector autoregressions with stochastic volatility to investigate changes in reduced‐form and structural correlations between inventories and either sales growth or the real interest rate in the USA during both the inter‐war and post‐World War II periods. We identify four structural shocks by combining a single long‐run restriction to identify a permanent output shock with three sign restrictions to identify demand‐ and supply‐side transitory shocks. We show that during both the inter‐war and post‐war periods the structural correlation between inventories and real interest rate conditional on identified interest rate shocks is systematically positive; the reduced‐form correlation between the two series is positive during the post‐war period, but in line with the predictions of theory it is robustly negative during the inter‐war era; during that era the correlations between inventories and either of the two other series exhibit a remarkably strong co‐movement with output at business cycle frequencies. Copyright © 2014 John Wiley & Sons, Ltd.     

Sustainable entrepreneurship and the Sustainable Development Goals: Community-led initiatives,the social solidarity economy and commons ecologies

The social solidarity economy is an approach to the production and consumption of goods, services and knowledge that promises to address contemporary economic, social and environmental crises more effectively than business as usual. The paper employs the concept of commons ecologies to examine the practices, relationships and interactions among actors and organisations in the social solidarity economy, as well as between them and the mainstream economy, which shape the field and its degree of autonomy in relation to capitalism, through a process defined as boundary commoning. Such process shapes both local and regional commons ecologies, as well as the participation of local and regional actors in wider networks at national, international and global levels. The paper takes a case study-based approach to identify practices, relationships and interactions of commons ecologies in relation to selected community-led initiatives in the UK, Portugal, Brazil and Senegal. Each case study illuminates different qualities of local/regional commons ecologies and their forms of engagement with wider networks. Further, the paper shows that these cases demonstrate how the social solidarity economy may facilitate delivery of the Sustainable Development Goals in a distinctive way. In each case, SSE acts as a vehicle for expressing participants' values and principles consistent with those underlying the SDGs. Local implementation of SDGs is thus an in-built feature of these commons ecologies. The participation of community-led initiatives in international and global networks offers opportunities to learn from local level experiences and successes, potentially strengthening SDG implementation more generally.     

Migration,Unemployment, and Skill Downgrading

In this paper, we analyze the labor market impacts of immigration under flexible and rigid labor market regimes. A general equilibrium framework is developed, accounting for skill heterogeneity and labor market frictions, where unemployed medium‐skilled manufacturing workers are downgraded into low‐skilled service jobs, while low‐skilled service workers might end up unemployed. The analytical analysis shows that medium‐skill immigration decreases low‐skilled unemployment under the flexible regime, indicating a complementarity effect, while the rigid regime induces a substitution effect, leading to low‐skilled unemployment. Moreover, it leads to wage polarization. In a numerical analysis, the economic effects of different migration scenarios are quantified.     

Variable Selection in Cross‐Section Regressions: Comparisons and Extensions

Cross‐section regressions often examine many candidate regressors. We use multiple testing procedures (MTPs) controlling the false discovery rate (FDR) — the expected ratio of false to all rejections — so as not to erroneously select variables because many tests were performed, yielding a simple model selection procedure. Simulations comparing the MTPs with other common model selection criteria demonstrate that, for conventional tuning parameters of the selection procedures, only MTPs consistently control the FDR, but have slightly lower power. In an empirical application to growth, MTPs and PcGets/Autometrics identify similar growth determinants, which differ somewhat from those obtained by Bayesian Model Averaging.