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Off-policy evaluation in doubly inhomogeneous environments
No full textThis work aims to study off-policy evaluation (OPE) under scenarios where two key reinforcement learning (RL) assumptions—temporal stationarity and individual homogeneity are both violated. To handle the “double inhomogeneities”, we propose a class of latent factor models for the reward and transition functions, under which we develop a general OPE framework that consists of both model-based and model-free approaches. To our knowledge, this is the first article that develops statistically sound OPE methods in offline RL with double inhomogeneities. It contributes to a deeper understanding of OPE in environments, where standard RL assumptions are not met, and provides several practical approaches in these settings. We establish the theoretical properties of the proposed value estimators and empirically show that our approach outperforms state-of-the-art methods. Finally, we illustrate our method on a dataset from the Medical Information Mart for Intensive Care. An R implementation of the proposed procedure is available at https://github.com/ZeyuBian/2FEOPE. Supplementary materials for this article are available online, including a standardized description of the materials available for reproducing the work
The solution to an impulse control problem motivated by optimal harvesting
No full textWe consider a stochastic impulse control problem that is motivated by applications such as the optimal exploitation of a natural resource. In particular, we consider a stochastic system whose uncontrolled state dynamics are modelled by a non-explosive positive linear diffusion. The control that can be applied to this system takes the form of one-sided impulsive action. The objective of the control problem is to maximise a discounted performance criterion that rewards the effect of control action but involves a fixed cost at each time of a control intervention. We derive the complete solution to this problem under general assumptions. It turns out that the solution can take four qualitatively different forms, several of which have not been observed in the literature. In two of the four cases, there exist only ε-optimal control strategies. We also show that the boundary classification of 0 may play a critical role in the solution of the problem. Furthermore, we develop a way for establishing the strong solution to a stochastic impulse control problem's optimally controlled SDE
Mobile internet and the quality of elections in low-income democracies
No full textHow does rising access to the Internet shape elections in low-income democracies? In a controversial, overturned election in Malawi, I show how online exposure can reduce incumbency advantages and improve election administration. Leveraging geocoded polling station returns and the expansion of 3G coverage in a difference-in-differences setting, I show that ruling party vote share and election irregularities decline in areas newly exposed to the Internet. This is robust to a series of specifications, including matching on pre-treatment characteristics and adjusting for polling station complexity. To examine mechanisms, I turn to interviews and focus group discussions with voters, party figures and election officials. These reveal that opposition groups used social media to campaign and organise, online platforms expanded the reach of civic education efforts, and election staff used WhatsApp to coordinate on polling day. The paper contributes to the literature on information technology, party strategy, and election administration in low-income settings
Fairness, ambiguity and dynamic consistency
No full textConsiderations of dynamic inconsistency have figured prominently in debates over the rationality of preferences that violate the separability conditions characteristic of expected utility theory. These debates have mostly focused on risk- and ambiguity averse preferences, but analogous considerations apply to preferences for fairness. We revisit these debates in the context of a specific hypothesis regarding the violations of separability by such preferences, namely that they are potentially both explained and rationalised by non-instrumental attitudes to the chances of the various possibilities involved. Our main aim is to argue that, first, when these violations of static separability are motivated by such non-instrumental attitudes to chances, then they need not result in dynamically inconsistent behaviour. Second, and more generally, considerations of dynamic consistency do not, we argue, undermine the rationality of non-instrumental attitudes towards the distribution of chances, despite the fact that such attitudes give rise to violations of the static separability assumptions of expected utility theory
The political economy of skills, occupational entitlements, and social mobility: evidence from industrializing Coventry, 1790-1850
No full textThis paper examines the interaction between political economy and social mobility during early industrialization in England. We analyze changes in male social mobility patterns in industrializing Coventry (c.1790–1850) following a transformation of key institutions affecting the labor market. Social mobility was framed by the interaction between trade policy, occupational skill formation, and municipal government. Using a longitudinal dataset and regression-discontinuity analysis, we find that liberal reforms to trade policy and municipal government during the late-1820s and early-1830s eroded the value of industry-specific social capital, while increasing the contribution of general human capital to social mobility
Labor market effects of global supply chain disruptions
No full textWe examine the labor market consequences of global supply chain disruptions. Specifically, we consider a temporary increase in international trade costs similar to the one observed during the COVID-19 pandemic and analyze its effects on labor market outcomes using a quantitative trade model with downward nominal wage rigidities. The increase in trade costs leads to a temporary but prolonged decline in U.S. labor force participation. However, there is a temporary increase in manufacturing employment as the United States is a net importer of manufactured goods, which become costlier to obtain from abroad. By contrast, service and agricultural employment experience temporary declines. Nominal frictions lead to temporary unemployment when the shock dissipates, but this depends on the degree of monetary accommodation. Overall, the shock results in an 8.5 basis points welfare loss for the United States. The impact on labor force participation and welfare across countries varies depending on the initial degree of openness and sectoral deficits
Apprenticeship, work, society in early modern Venice. Eds Anna Bellavitis and Valentina Sapienza, (Routledge, 2023. Pp. 304. 66B/W illustrations. ISBN 9781032053516 HbK £125)
No full textEffects of mosquito-proofing storm drains on adult and larvae mosquito abundance: protocol of the IDAlErt storm drAin randomiSed controlled trial (IDEAS)
No full textAedes and Culex mosquitoes, known for spreading arboviruses like dengue and West Nile, thrive in cities, posing health risks to urban populations. Climate change can create suitable climatic conditions for these vectors to spread further in Europe. Cities contain numerous landscape and infrastructure elements, such as storm drains, that allow stagnant water build-up facilitating mosquito breeding. Modifying urban infrastructure to prevent water accumulation can reduce mosquito populations, but evidence is limited. The Public Health Agency of Barcelona, Spain, introduced a structural modification of storm drains to prevent water accumulation. Together with the Agency, we designed a randomised controlled trial (RCT) to experimentally assess the effectiveness of these modifications on adult Aedes albopictus and Culex pipiens populations. It is a parallel-arm RCT with equal randomization of 44 drains to receive mosquito-proofing modifications (intervention) or not (control). Primary outcomes are adult mosquito counts and secondary outcomes are larvae and mosquito presence, assessed weekly at each drain until no mosquitoes are detected. Data analyses include generalised linear mixed models to estimate the time-averaged and highest intervention effects, subgroup and sensitivity analyses. The trial results will guide a city-wide expansion of the storm drain modifications and provide valuable evidence to enhance existing vector control measures
The control of “wandering women” the legacy of vagrancy laws in the contemporary governance of migrant sex work
No full textThis paper traces the contemporary governance of migrant sex work to early vagrancy laws aimed at controlling poor mobile populations and people not engaging in ‘honest’ labor. The paper argues that these notions of dishonest labor are still visible in the contemporary crimmigration controls. It uses a legal analysis of the development of prostitution and immigration laws together with ethnographic research in the Nordic region as a case study to develop an argument on the bifurcated regulation of domestic and foreign sex work and its roots in the vagrancy laws. It makes the case that with the influx of migrants into the sex trade since the 1990s the governance of commercial sex has shifted from prostitution policies to immigration controls
The haunted happiness of racialised beauty: a performative theoretical view
No full textThis chapter concerns the racialised meanings and politics of black women’s embrace of hair weaves and wigs as technologies of feminine beautification, and feelings of happiness therein. Based on interviews with 18 young Nigerian women who dress and feel this way, the chapter seeks to decentre easy and ready readings of them as subjects who are wanting or trying to be ‘white.’ Instead it makes a case for understanding and allowing that weaves and wigs have become technologies of blackness, albeit haunted as such by the violence of the very notion of race as well as ongoing histories of anti-black racism. The argument is premised on a theoretical understanding of blackness as a performatively constituted category of being, that is to say, a material and cultural construct that is made in the repeated doing, inscribing and embodying of it, such that it cannot be fixed but rather can be, and is, fashioned in multiple and changing ways