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Robust tobit regression for censored observations using extended Box-Cox Transformations
No full textTruncated regression data often occur in measuring consumer behaviour involving infrequent purchases. We consider data with truncation of the upper and lower tails of the response distribution at arbitrary values. If, in addition, the distribution of responses is also skewed, we use robust transformations of the response with the parametric Yeo–Johnson transformation to provide approximate normality for both positive and negative responses. Tests for the value of the transformation parameter use the signed square root of the loglikelihood ratio test. To achieve robustness we use the Forward Search which fits the model to data subsets of increasing size and so orders the observations by closeness to the fitted model. Monitoring the statistic for transformation during the Forward Search indicates an appropriate transformation. We initially exhibit the properties of our procedure on simulated data. Our practical regression analysis is of 493 observations derived from loyalty card data. 100 of the responses are censored at zero and there are ten explanatory variables
The gender gap in carbon footprints: determinants and implications
No full textUnderstanding the distribution of carbon footprints across population groups is crucial for designing fair and acceptable climate policies. Using granular consumption data from France, we quantify the gender gap in carbon footprints related to food and transport and investigate its underlying drivers. We show that women emit 26% less carbon than men in these two sectors, which together account for half of the average individual carbon footprint. Socioeconomic factors, biological differences and gender differences in distances traveled explain part of the gap, but up to 38% remains unexplained. Red meat and car — high-emission goods often associated with male identity — account for most of the residual, highlighting the role of gender differences in preferences in shaping disparities in carbon footprints
Coffee, Ceylon and Kew Gardens: the hard work of maintaining a plantation system through plantation science
No full textPlantation agriculture contains a central paradox: the very formula which makes it productive, also makes it susceptible to the existential threat of crop disease. This article explores this paradox in the coffee plantations of nineteenth-century Ceylon which were threatened by the pathological fungus Hemelia vastatrix (coffee leaf rust), analysing the response led by Kew Gardens. Ultimately, the story of coffee plantations in Ceylon is of failure, but the planation system endured after being reworked with cinchona and tea. The article examines Kew's response and why coffee plantations failed but the plantation system was maintained. The article develops the concept of plantation science to term this maintenance, arguing acts of knowing conducted by actors become the basis for subsequent acts of management. Using the analytics of plantation science indicates the hard work of maintaining the plantation system. The plantation system is dominant, but that domination requires effort, and exploring that effort shows its relative precarity. The article uses Kew Garden's archives to offer empirical insight into a colonial plantation system, imperial Kew Gardens and a contested scientific response. The article concludes with reflections on the durability of the plantation, and the intersection of the plantation science and climate change adaptation
False hope and fictitious patents: evaluating the intellectual property of OxyContin
No full textIn this article I evaluate the socio-legal process of transforming a scientific R&D output into a market commodity via the prism of a public health crisis, namely, the opioid epidemic in the United States (US). My jurisdictional focus on the US is justified by its position at the epicentre of the opioid crisis, as well as being the most prominent patent and regulatory jurisdiction for the global pharmaceutical market. I undertake the first substantive examination of OxyContin from an IP law perspective, exploring its trajectory from conception to market, considering what lessons can be learned for IP theory and practice. Overall, I contribute a novel theoretical approach, examining patented pharmaceuticals as products of industrialised hope, while evaluating a practical case study of one such commodity, OxyContin. I conclude that the case of OxyContin highlights several problems inherent to the current system, including misaligned incentives, inadequate patent examination, and insufficient regulation
Referencing drug prices of other countries may not sustainably lower prices in the United States: lessons from Europe
No full textThe Trump Administration issued an Executive Order on May 12, 2025, with the intent to “equalize pricing across developed countries” through a “Most-Favored Nation” approach with international reference pricing (IRP). IRP has been used extensively in Europe and resulted in short-term budget savings. However, list prices quickly converged to those of major high-income markets, such as Germany and France, without evidence of reduced prices. Despite frequent use of confidential price agreements to differentiate net prices in countries that cannot afford those price levels, access to innovative medicines has been delayed and reduced. This suggests that introduction of IRP in the United States could further limit access in designated reference countries, without sustainable reductions in US price levels. Instead of referencing prices from other countries, the United States should establish its own system for value assessment of medicines, whether at the time of launch or after drugs have been on the market for several years
Building blocks of value creation within value-based health systems: a Delphi study
No full textObjectives Health technologies can provide significant value to health systems; however, identifying and structuring the factors that drive this value is crucial for informed resource allocation. This study aims to develop a consensus-driven framework that defines the key factors influencing value creation in health technologies and identifies system-level barriers that may limit their potential impact. Methods A mixed-method approach was used, starting with a targeted review, resulting in 21 frameworks that informed an initial framework draft. A 3-round web-based Delphi exercise was conducted with 22 experts from academia, industry, patient representation, policy making, and healthcare regulation. In round 1, participants contributed value statements—specific characteristics influencing value creation—within the initial framework. Thematic analysis using NVivo consolidated these into a comprehensive framework. Rounds 2 and 3 involved participants rating the importance of these cocreated statements on a 5-point Likert scale. Results The scoping review yielded 10 value domains (politics, health system organization, governance, financing, geographic features, population health, resource generation, providers, private industry, and technology features) with 46 subdomains. The Delphi exercise ultimately generated 61 value statements for 38 subdomains, with 17 achieving consensus and stability. Conclusions The resulting value framework offers an evidence-based, system-centered approach to value assessment, incorporating diverse stakeholder perspectives and system factors. This approach addresses gaps in current value capture. Future research should focus on validating the domains and subdomains identified in this framework across different healthcare settings
Investor memory and biased beliefs: evidence from the field
No full textWe survey a large, representative sample of retail investors in China to elicit their memories of stock market investments and their return expectations. We merge these survey data with administrative transaction data to test a model in which investors selectively recall past experiences to form their beliefs. Our analysis uncovers new facts about investor memory and highlights similarity-based recall as a key mechanism of belief formation in financial markets. A rising market prompts investors to recall their past experiences more positively, leading to more optimistic forecasts of future returns. Recalled experiences can explain cross-investor variation in return expectations and, in our setting, dominate actual experiences in their explanatory power. In the transaction data, we confirm that recalled experiences are reflected in investors’ trading decisions through a belief channel
Hiding in plain sight: IDP’s protection strategies after closing Juba’s protection of civilian sites
No full textThis article examines how former Protection of Civilian site (PoCs) residents are staying safe and protecting themselves after the United Nations Mission in South Sudan's (UNMISS) handing over of the PoCs to the Revitalised-Transitional Government of National Unity (R-TGoNU). Using key informant interviews, questionnaires, and observations, we establish that those still residing in the PoCs do so with less humanitarian assistance, increased insecurity, and few authorities they can rely upon or turn to for protection. In response, it is shown how camp residents have developed their own safety and protection strategies at the cost of their ability to pursue livelihoods, move freely outside of the camps, and publicly express their identities. Although broadly stable, this situation is unsustainable and risks the safety of camp residents and the wider ongoing peace process. The paper concludes with policy recommendations for humanitarians and R-TGoNU policymakers interested in their welfare
Induced innovation, inventors, and the energy transition
No full textWe study how individual inventors respond to incentives to work on “clean” electricity technologies. Using natural gas price variation, we estimate output and entry elasticities of inventors and measure the medium-term impacts of a price increase mirroring the social cost of carbon. We find that the induced clean innovation response primarily comes from existing clean inventors. New inventors are less responsive on the margin than their average contribution to clean energy patenting would indicate. Our results strengthen the rationale for government intervention to expedite the energy transition
Skill-biased technical change, again? Online gig platforms and local employment
No full textOnline gig platforms have the potential to influence employment in existing industries. Popular press and academic research offer two competing predictions: First, online gig platforms may reduce the supply of incumbent workers by intensifying competition and obsoleting certain skills of workers; or, second, they may boost the supply of workers by increasing client-worker matching efficiency and creating new employment opportunities for workers. Yet, there has been limited understanding of the labor movements amid the rise of online gig platforms. Extending the Skill-Biased Technical Change literature, we study the impact of TaskRabbit—a location-based gig platform that matches freelance workers to local demand for domestic tasks (e.g., cleaning services)—on the local supply of incumbent, work-for-wages housekeeping workers. We also examine the effect heterogeneity across workers at different skill levels. Exploiting the staggered TaskRabbit expansion into U.S. cities, we identify a significant decrease in the number of incumbent housekeeping workers after TaskRabbit entry. Notably, this is mainly driven by a disproportionate decline in the number of middle-skilled workers (i.e., first-line managers, supervisors) whose tasks could easily be automated by TaskRabbit’s matching algorithms, but not low-skilled workers (i.e., janitors, cleaners) who typically perform manual tasks. Interestingly, TaskRabbit entry does not necessarily crowd out middle-skilled housekeeping workers, neither laying them off nor forcing them to other related occupations; rather, TaskRabbit entry supports self-employment within the housekeeping industry. These findings imply that online gig platforms may not naively be viewed as skill-biased, especially for low-skilled workers; instead, they redistribute middle-skilled, managerial workers whose cognitive tasks are automated by the sorting and matching algorithms to explore new self-employment opportunities for workers, stressing the need to reconsider online gig platforms as a means to reshape existing industries and stimulate entrepreneurial endeavors