Probabilistic access forecasting for improved offshore operations

Improving access is a priority in the offshore wind sector, driven by the opportunity to increase revenues, reduce costs, and improve safety at operational wind farms. This paper describes a novel method for producing probabilistic forecasts of safety-critical access conditions during crew transfers. Methods of generating density forecasts of significant wave height and peak wave period are developed and evaluated. It is found that boosted semi-parametric models outperform those estimated via maximum likelihood, as well as a non-parametric approach. Scenario forecasts of sea-state variables are generated and used as inputs to a data-driven vessel motion model, based on telemetry recorded during 700 crew transfers. This enables the production of probabilistic access forecasts of vessel motion during crew transfer up to 5 days ahead. The above methodology is implemented on a case study at a wind farm off the east coast of the UK.     

The structure of information release and the factor structure of returns

We model how firms releasing information on different dates causes the CAPM to fail, requiring an additional factor based on the information structure to price assets. We exemplify this mechanism’s empirical relevance using quarterly earnings announcements, which cluster across months along size and book-to-market. Seventy percent of the alpha reduction from including SMB and HML occurs in the four main earnings announcement months. The information structure factor accounts for all of SMB and HML’s seasonal alpha reduction and one third of their overall alpha reduction. Controlling for size and book-to-market, exposures to SMB and HML vary with firms’ earnings announcement month.     

Marx,Sraffa, and Surplus: Observations Prompted by Garegnani (2018)

ABSTRACT

In a posthumously published article, Pierangelo Garegnani (2018. ‘On the Labour Theory of Value in Marx and in the Marxist Tradition.’) depicts Marx’s project in Capital as that of ‘developing systematically the theory of Ricardo and [the] implications of social conflict’ implied by Ricardo’s ‘surplus approach to value and distribution’. This paper argues to the contrary that Marx’s theory of surplus value and exploitation differs from (neo-)Ricardian surplus theory in fundamental ways, and modifies Garegnani’s simple Sraffian model to illustrate the distinctive implications of Marx’s theory.     

Territorialization in a closing commodity frontier: The Yasuní rainforests of West Amazonia

In Ecuador's Yasuní rainforests and the lived history of the Waorani that live there, the commodification of first rubber and then oil shaped territorialization into particularly violent form. The formative role of rubber production in the 19th century involved local despots' imposition of a regime of violence. Reacting to this violent capitalist system, individual Waorani forged new socio‐spatial territories through violence with rubber slavers and cooperation with the Taromenane, a people who continue to live in isolation. Today, an oil complex exerts control to bring the end of Yasuní's commodity frontier, even while the Waorani Nation and Taromenane hold legal rights to parts of the forests. In this article, I analyse how rubber and oil exploitation has unfolded as capitalist territorial violence, spurring Waorani and Taromenane social expressions and political mobilizations that are at times violent, but primarily not.     

‘Consumer Ethics: The Role of Acculturation in U.S. Immigrant Populations’

This study examines the role of acculturation in shaping consumers’ views of ethics. Specifically, it examines the relationships between the desire to keep one’s original culture, the desire to adopt the host culture, and the four dimensions of the Muncy and Vitell (Journal of Business Research Ethics 24(4), 297, 1992) consumer ethics scale. Using two separate immigrant populations – one of former Middle-Eastern residents now living in the U.S. and the other of Asian immigrants in the U.S. – results indicate that those who want to keep their original culture are less tolerant of unethical consumer activities, while those who are more willing to adopt the host culture are more tolerant of these same consumer activities. Furthermore, the immigrants in both studies who are more tolerant of unethical consumer activities are those who are generally somewhat younger and with less formal education. The relationship between gender and consumer ethics was not significant.     

Licensing and innovation with imperfect contract enforcement

Licensing promotes technology transfer and innovation, but enforcement of licensing contracts is often imperfect. We model contract enforcement as a game with perfect information but probabilistic enforcement and explore the implications of weak enforcement on the design of licensing contracts, the conduct of firms, and market performance. An upstream firm develops a technology that it can license to downstream firms using a fixed fee and a per‐unit royalty. Strictly positive per‐unit royalties maximize the licensor's profit if competition among licensees limits joint profits. With imperfect enforcement, the licensor lowers variable royalties to avoid cheating. Although imperfect contract enforcement reduces the profits of the licensor, weak enforcement lowers prices, increases downstream innovation, and in some circumstances can increase total economic welfare.     

On the Relation between Local Amenities and House Price Dynamics

This study explores the extent to which local amenities are related to house price volatility, returns and risk‐adjusted returns across 238 MSAs. We find strong evidence that high amenity areas experience greater price volatility. In regards to returns, high amenity areas experience greater (lower) real returns in appreciating (depreciating) markets. However, high amenity areas experience little to no abnormal risk‐adjusted returns. Results from the study are robust to an endogenous treatment of amenities and land supply elasticity. Overall, we conclude that the desirability of a metropolitan area is a significant channel through which land values drive house price dynamics.     

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.     

Estimating the Enduring Effects of Fertiliser Subsidies on Commercial Fertiliser Demand and Maize Production: Panel Data Evidence from Malawi

Most studies of input subsidy programmes confine their analyses to measuring programme effects over a one‐year period. This article estimates the potential longer‐run or enduring effects of fertiliser subsidy programmes on smallholder farm households' demand for commercial fertiliser and maize production over time. We use four waves of panel data on 462 farm households in Malawi for whom fertiliser use can be tracked for eight consecutive seasons between 2003/2004 and 2010/2011. Panel estimation methods are used to control for potential endogeneity of subsidised fertiliser acquisition. Results indicate that farmers acquiring subsidised fertiliser in three consecutive prior years are found to purchase slightly more commercial fertiliser in the next year. This suggests a small amount of crowding in of commercial fertiliser from the receipt of subsidised fertiliser in prior years. In addition, acquiring subsidised fertiliser in a given year has a modest positive impact on increasing maize output in that same year. However, acquiring subsidised fertiliser in multiple prior years generates no statistically significant effect on maize output in the current year. These findings indicate that potential enduring effects of the Malawi fertiliser subsidy programme on maize production are limited. Additional interventions that increase soil fertility can make using inorganic fertiliser more profitable and sustainable for smallholders in sub‐Saharan Africa and thereby increase the cost‐effectiveness of input subsidy programmes.