Showing papers by "London School of Economics and Political Science published in 2017"

Social isolation, loneliness and health in old age: a scoping review.

Abstract: The health and well-being consequences of social isolation and loneliness in old age are increasingly being recognised The purpose of this scoping review was to take stock of the available evidence and to highlight gaps and areas for future research We searched nine databases for empirical papers investigating the impact of social isolation and/or loneliness on a range of health outcomes in old age Our search, conducted between July and September 2013 yielded 11,736 articles, of which 128 items from 15 countries were included in the scoping review Papers were reviewed, with a focus on the definitions and measurements of the two concepts, associations and causal mechanisms, differences across population groups and interventions The evidence is largely US-focused, and loneliness is more researched than social isolation A recent trend is the investigation of the comparative effects of social isolation and loneliness Depression and cardiovascular health are the most often researched outcomes, followed by well-being Almost all (but two) studies found a detrimental effect of isolation or loneliness on health However, causal links and mechanisms are difficult to demonstrate, and further investigation is warranted We found a paucity of research focusing on at-risk sub-groups and in the area of interventions Future research should aim to better link the evidence on the risk factors for loneliness and social isolation and the evidence on their impact on health

QSGD: Communication-Efficient SGD via Gradient Quantization and Encoding

Abstract: Parallel implementations of stochastic gradient descent (SGD) have received significant research attention, thanks to its excellent scalability properties. A fundamental barrier when parallelizing SGD is the high bandwidth cost of communicating gradient updates between nodes; consequently, several lossy compresion heuristics have been proposed, by which nodes only communicate quantized gradients. Although effective in practice, these heuristics do not always guarantee convergence, and it is not clear whether they can be improved. In this paper, we propose Quantized SGD (QSGD), a family of compression schemes for gradient updates which provides convergence guarantees. QSGD allows the user to smoothly trade off \emph{communication bandwidth} and \emph{convergence time}: nodes can adjust the number of bits sent per iteration, at the cost of possibly higher variance. We show that this trade-off is inherent, in the sense that improving it past some threshold would violate information-theoretic lower bounds. QSGD guarantees convergence for convex and non-convex objectives, under asynchrony, and can be extended to stochastic variance-reduced techniques. When applied to training deep neural networks for image classification and automated speech recognition, QSGD leads to significant reductions in end-to-end training time. For example, on 16GPUs, we can train the ResNet152 network to full accuracy on ImageNet 1.8x faster than the full-precision variant.

The Institutionalization of Global AIDS and the Creation of the Joint United Nations Programme on HIV/AIDS (UNAIDS)

Abstract: This chapter focuses on the creation of the Joint United Nations Programme on HIV/AIDS (UNAIDS), and how this new formation set about institutionalizing a global AIDS perspective. The chapter considers the main motivations behind this creation, which included the need to create a coherent and shared understanding of HIV, together with a coordinated policy framework to bring together different technical and political capacities for coherent policy intervention in multiple country contexts. The chapter argues that this process of creating a shared understanding of expected outcomes led to a shared understanding of the disease laying the foundations for the politics of Global AIDS.

Availability of evidence of benefits on overall survival and quality of life of cancer drugs approved by European Medicines Agency: retrospective cohort study of drug approvals 2009-13

Abstract: Objective To determine the availability of data on overall survival and quality of life benefits of cancer drugs approved in Europe. Design Retrospective cohort study. Setting Publicly accessible regulatory and scientific reports on cancer approvals by the European Medicines Agency (EMA) from 2009 to 2013. Main outcome measures Pivotal and postmarketing trials of cancer drugs according to their design features (randomisation, crossover, blinding), comparators, and endpoints. Availability and magnitude of benefit on overall survival or quality of life determined at time of approval and after market entry. Validated European Society for Medical Oncology Magnitude of Clinical Benefit Scale (ESMO-MCBS) used to assess the clinical value of the reported gains in published studies of cancer drugs. Results From 2009 to 2013, the EMA approved the use of 48 cancer drugs for 68 indications. Of these, eight indications (12%) were approved on the basis of a single arm study. At the time of market approval, there was significant prolongation of survival in 24 of the 68 (35%). The magnitude of the benefit on overall survival ranged from 1.0 to 5.8 months (median 2.7 months). At the time of market approval, there was an improvement in quality of life in seven of 68 indications (10%). Out of 44 indications for which there was no evidence of a survival gain at the time of market authorisation, in the subsequent postmarketing period there was evidence for extension of life in three (7%) and reported benefit on quality of life in five (11%). Of the 68 cancer indications with EMA approval, and with a median of 5.4 years’ follow-up (minimum 3.3 years, maximum 8.1 years), only 35 (51%) had shown a significant improvement in survival or quality of life, while 33 (49%) remained uncertain. Of 23 indications associated with a survival benefit that could be scored with the ESMO-MCBS tool, the benefit was judged to be clinically meaningful in less than half (11/23, 48%). Conclusions This systematic evaluation of oncology approvals by the EMA in 2009-13 shows that most drugs entered the market without evidence of benefit on survival or quality of life. At a minimum of 3.3 years after market entry, there was still no conclusive evidence that these drugs either extended or improved life for most cancer indications. When there were survival gains over existing treatment options or placebo, they were often marginal.

Roads, Railroads, and Decentralization of Chinese Cities

Abstract: We investigate how the configurations of urban railroads and highways have influenced urban form in Chinese cities since 1990. Each radial highway displaces at least 5 percent of central city population to surrounding regions and ring roads displace an additional 20 percent. Each radial railroad displaces 26 percent of central city industrial GDP with ring roads displacing an additional 50 percent. Products with high weight-to-value ratios appear unresponsive to transport changes. However, products with medium and low weight-to-value ratios decentralize in response to radial railroads and ring roads. Historical transportation infrastructure provides identifying variation in more recent measures of infrastructure. J.E.L.: R4, O2

Mental Health Service Provision in Low- and Middle-Income Countries.

Abstract: This article discusses the provision of mental health services in low- and middle-income countries (LMICs) with a view to understanding the cultural dynamics–how the challenges they pose can be addressed and the opportunities harnessed in specific cultural contexts. The article highlights the need for prioritisation of mental health services by incorporating local population and cultural needs. This can be achieved only through political will and strengthened legislation, improved resource allocation and strategic organisation, integrated packages of care underpinned by professional communication and training, and involvement of patients, informal carers, and the wider community in a therapeutic capacity.

The impacts of environmental regulations on competitiveness

Abstract: This article reviews the empirical literature on the impacts of environmental regulations on firms’ competitiveness as measured by trade, industry location, employment, productivity, and in...

Revisiting Event Study Designs

Abstract: A broad empirical literature uses "event study" research designs for treatment effect estimation, a setting in which all units in the panel receive treatment but at random times. We make four novel points about identification and estimation of causal effects in this setting and show their practical relevance. First, we show that in the presence of unit and time fixed effects, it is impossible to identify the linear component of the path of pre-trends and dynamic treatment effects. Second, we propose graphical and statistical tests for pre-trends. Third, we consider commonly-used "static" regressions, with a treatment dummy instead of a full set of leads and lags around the treatment event, and we show that OLS does not recover a weighted average of the treatment effects: long-term effects are weighted negatively, and we introduce a different estimator that is robust to this issue. Fourth, we show that equivalent problems of under-identification and negative weighting arise in difference-in-differences settings when the control group is allowed to be on a different time trend or in the presence of unit-specific time trends. Finally, we show the practical relevance of these issues in a series of examples from the existing literature, with a focus on the estimation of the marginal propensity to consume out of tax rebates.

What is the Expected Return on the Market

Abstract: I derive a lower bound on the equity premium in terms of a volatility index, SVIX, that can be calculated from index option prices. The bound implies that the equity premium is extremely volatile and that it rose above 20% at the height of the crisis in 2008. The time-series average of the lower bound is about 5%, suggesting that the bound may be approximately tight. I run predictive regressions and find that this hypothesis is not rejected by the data, so I use the SVIX index as a proxy for the equity premium and argue that the high equity premia available at times of stress largely reflect high expected returns over the very short run. I also provide a measure of the probability of a market crash, and introduce simple variance swaps, tradable contracts based on SVIX that are robust alternatives to variance swaps.

Are Ideas Getting Harder to Find

Abstract: In many growth models, economic growth arises from people creating ideas, and the long-run growth rate is the product of two terms: the effective number of researchers and their research productivity. We present a wide range of evidence from various industries, products, and firms showing that research effort is rising substantially while research productivity is declining sharply. A good example is Moore's Law. The number of researchers required today to achieve the famous doubling every two years of the density of computer chips is more than 18 times larger than the number required in the early 1970s. Across a broad range of case studies at various levels of (dis)aggregation, we find that ideas — and in particular the exponential growth they imply — are getting harder and harder to find. Exponential growth results from the large increases in research effort that offset its declining productivity.

Smart and Illicit: Who Becomes an Entrepreneur and Do They Earn More?

Abstract: We disaggregate the self-employed into incorporated and unincorporated to distinguish between “entrepreneurs” and other business owners. We show that the incorporated self-employed and their businesses engage in activities that demand comparatively strong nonroutine cognitive abilities, while the unincorporated and their firms perform tasks demanding relatively strong manual skills. People who become incorporated business owners tend to be more educated and— as teenagers—score higher on learning aptitude tests, exhibit greater self-esteem, and engage in more illicit activities than others. The combination of “smart” and “illicit” tendencies as youths accounts for both entry into entrepreneurship and the comparative earnings of entrepreneurs. Individuals tend to experience a material increase in earnings when becoming entrepreneurs, and this increase occurs at each decile of the distribution.

Maximizing Opportunities and Minimizing Risks for Children Online: The Role of Digital Skills in Emerging Strategies of Parental Mediation

Abstract: As internet use becomes widespread at home, parents are trying to maximize their children’s online opportunities while also minimizing online risks. We surveyed parents of 6- to 14-year-olds in eight European countries (N=6,400). A factor analysis revealed two strategies. Enabling mediation is associated with increased online opportunities but also risks. This strategy incorporates safety efforts, responds to child agency and is employed when parent or child is relatively digitally skilled, so may not support harm. Restrictive mediation is associated with fewer online risks but at the cost of opportunities, reflecting policy advice that regards media use as primarily problematic. It is favoured when parent or child digital skills are lower, potentially keeping vulnerable children safe yet undermining their digital inclusion.

Potential applications of subseasonal-to-seasonal (S2S) predictions

Abstract: While seasonal outlooks have been operational for many years, until recently the extended-range timescale referred to as subseasonal-to-seasonal (S2S) has received little attention. S2S prediction fills the gap between short-range weather prediction and long-range seasonal outlooks. Decisions in a range of sectors are made in this extended-range lead time; therefore, there is a strong demand for this new generation of forecasts. International efforts are under way to identify key sources of predictability, improve forecast skill and operationalize aspects of S2S forecasts; however, challenges remain in advancing this new frontier. If S2S predictions are to be used effectively, it is important that, along with science advances, an effort is made to develop, communicate and apply these forecasts appropriately. In this study, the emerging operational S2S forecasts are presented to the wider weather and climate applications community by undertaking the first comprehensive review of sectoral applications of S2S predictions, including public health, disaster preparedness, water management, energy and agriculture. The value of applications-relevant S2S predictions is explored, and the opportunities and challenges facing their uptake are highlighted. It is shown how social sciences can be integrated with S2S development, from communication to decision-making and valuation of forecasts, to enhance the benefits of ‘climate services’ approaches for extended-range forecasting. While S2S forecasting is at a relatively early stage of development, it is concluded that it presents a significant new window of opportunity that can be explored for application-ready capabilities that could allow many sectors the opportunity to systematically plan on a new time horizon.

Ten simple rules for responsible big data research

Abstract: The use of big data research methods has grown tremendously over the past five years in both academia and industry. As the size and complexity of available datasets has grown, so too have the ethical questions raised by big data research. These questions become increasingly urgent as data and research agendas move well beyond those typical of the computational and natural sciences, to more directly address sensitive aspects of human behavior, interaction, and health. The tools of big data research are increasingly woven into our daily lives, including mining digital medical records for scientific and economic insights, mapping relationships via social media, capturing individuals’ speech and action via sensors, tracking movement across space, shaping police and security policy via “predictive policing,” and much more. The beneficial possibilities for big data in science and industry are tempered by new challenges facing researchers that often lie outside their training and comfort zone. Social scientists now grapple with data structures and cloud computing, while computer scientists must contend with human subject protocols and institutional review boards (IRBs). While the connection between individual datum and actual human beings can appear quite abstract, the scope, scale, and complexity of many forms of big data creates a rich ecosystem in which human participants and their communities are deeply embedded and susceptible to harm. This complexity challenges any normative set of rules and makes devising universal guidelines difficult. Nevertheless, the need for direction in responsible big data research is evident, and this article provides a set of “ten simple rules” for addressing the complex ethical issues that will inevitably arise. Modeled on PLOS Computational Biology’s ongoing collection of rules, the recommendations we outline involve more nuance than the words “simple” and “rules” suggest. This nuance is inevitably tied to our paper’s starting premise: all big data research on social, medical, psychological, and economic phenomena engages with human subjects, and researchers have the ethical responsibility to minimize potential harm. The variety in data sources, research topics, and methodological approaches in big data belies a one-size-fits-all checklist; as a result, these rules are less specific than some might hope. Rather, we exhort researchers to recognize the human participants and complex systems contained within their data and make grappling with ethical questions part of their standard workflow. Towards this end, we structure the first five rules around how to reduce the chance of harm resulting from big data research practices; the second five rules focus on ways researchers can contribute to building best practices that fit their disciplinary and methodological approaches. At the core of these rules, we challenge big data researchers who consider their data disentangled from the ability to harm to reexamine their assumptions. The examples in this paper show how often even seemingly innocuous and anonymized data have produced unanticipated ethical questions and detrimental impacts. This paper is a result of a two-year National Science Foundation (NSF)-funded project that established the Council for Big Data, Ethics, and Society, a group of 20 scholars from a wide range of social, natural, and computational sciences (http://bdes.datasociety.net/). The Council was charged with providing guidance to the NSF on how to best encourage ethical practices in scientific and engineering research, utilizing big data research methods and infrastructures [1].

Maximizing opportunities and minimizing risks for children online: the role of digital skills in emerging strategies of parental mediation

Abstract: As internet use becomes widespread at home, parents are trying to maximize their children’s online opportunities while also minimizing online risks. We surveyed parents of 6- to 14-year-olds in eight European countries (N=6,400). A factor analysis revealed two strategies. Enabling mediation is associated with increased online opportunities but also risks. This strategy incorporates safety efforts, responds to child agency and is employed when parent or child is relatively digitally skilled, so may not support harm. Restrictive mediation is associated with fewer online risks but at the cost of opportunities, reflecting policy advice that regards media use as primarily problematic. It is favoured when parent or child digital skills are lower, potentially keeping vulnerable children safe yet undermining their digital inclusion.

Austerity and health: the impact in the UK and Europe

Abstract: Austerity measures-reducing social spending and increasing taxation-hurts deprived groups the most. Less is known about the impact on health. In this short review, we evaluate the evidence of austerity's impact on health, through two main mechanisms: a 'social risk effect' of increasing unemployment, poverty, homelessness and other socio-economic risk factors (indirect), and a 'healthcare effect' through cuts to healthcare services, as well as reductions in health coverage and restricting access to care (direct). We distinguish those impacts of economic crises from those of austerity as a response to it. Where possible, data from across Europe will be drawn upon, as well as more extensive analysis of the UK's austerity measures performed by the authors of this review.

The costs and benefits of leaving the EU: trade effects

Abstract: This paper estimates the welfare effects of Brexit, focusing on trade and fiscal transfers. We use a standard quantitative general equilibrium trade model with many countries and sectors and trade in intermediates, as in Costinot and Rodriguez-Clare (2014). We simulate a range of counterfactuals reflecting alternative options for EU-UK relations following Brexit. Welfare losses for the average UK household are 1.3% if the UK remains in the EU's Single Market like Norway (a “soft Brexit”).Losses rise to 2.7% if the UK trades with the EU under World Trade Organization rules (a “hard Brexit”). A reduced form approach that captures the dynamic effects of Brexit on productivity more than riples these losses and implies a decline in average income per capita of between 6.3% and 9.4%, partly via falls in foreign investment. These negative effects are widely shared across the entire income distribution and are unlikely to be offset from new trade deals.

Factors associated with the quality of life of family carers of people with dementia: A systematic review

Abstract: Introduction Family carers of people with dementia are their most important support in practical, personal, and economic terms. Carers are vital to maintaining the quality of life (QOL) of people with dementia. This review aims to identify factors related to the QOL of family carers of people with dementia. Methods Searches on terms including "carers," "dementia," "family," and "quality of life" in research databases. Findings were synthesized inductively, grouping factors associated with carer QOL into themes. Results A total of 909 abstracts were identified. Following screening, lateral searches, and quality appraisal, 41 studies ( n = 5539) were included for synthesis. A total of 10 themes were identified: demographics; carer–patient relationship; dementia characteristics; demands of caring; carer health; carer emotional well-being; support received; carer independence; carer self-efficacy; and future. Discussion The quality and level of evidence supporting each theme varied. We need further research on what factors predict carer QOL in dementia and how to measure it.

Counting indirect crisis-related deaths in the context of a low-resilience health system: the case of maternal and neonatal health during the Ebola epidemic in Sierra Leone.

Abstract: Although the number of direct Ebola-related deaths from the 2013 to 2016 West African Ebola outbreak has been quantified, the number of indirect deaths, resulting from decreased utilization of routine health services, remains unknown. Such information is a key ingredient of health system resilience, essential for adequate allocation of resources to both 'crisis response activities' and 'core functions'. Taking stock of indirect deaths may also help the concept of health system resilience achieve political traction over the traditional approach of disease-specific surveillance. This study responds to these imperatives by quantifying the extent of the drop in utilization of essential reproductive, maternal and neonatal health services in Sierra Leone during the Ebola outbreak by using interrupted time-series regression to analyse Health Management Information System (HMIS) data. Using the Lives Saved Tool, we then model the implication of this decrease in utilization in terms of excess maternal and neonatal deaths, as well as stillbirths. We find that antenatal care coverage suffered from the largest decrease in coverage as a result of the Ebola epidemic, with an estimated 22 percentage point (p.p.) decrease in population coverage compared with the most conservative counterfactual scenario. Use of family planning, facility delivery and post-natal care services also decreased but to a lesser extent (-6, -8 and -13 p.p. respectively). This decrease in utilization of life-saving health services translates to 3600 additional maternal, neonatal and stillbirth deaths in the year 2014-15 under the most conservative scenario. In other words, we estimate that the indirect mortality effects of a crisis in the context of a health system lacking resilience may be as important as the direct mortality effects of the crisis itself.

The Country Chronologies to Exchange Rate Arrangements into the 21st Century: Will the Anchor Currency Hold?

Abstract: Detailed country-by-country chronologies are an informative companion piece to our paper “Exchange Arrangements Entering the 21st Century: Which Anchor Will Hold?,” which provides a comprehensive history of anchor or reference currencies, exchange rate arrangements, and a new measure of foreign exchange restrictions for 194 countries and territories over 1946-2016. The individual country chronologies are also a central component of our approach to classifying regimes. These country histories date dual or multiple exchange rate episodes, as well as to differentiate between pre-announced pegs, crawling pegs, and bands from their de facto counterparts. We think it is important to distinguish between say, de facto pegs or bands from announced pegs or bands, because their properties are potentially different. The chronologies also flag the dates for important turning points, such as when the exchange rate first floated, or when the anchor currency was changed. We extend our chronologies as far back as possible, even though we only classify regimes from 1946 onwards.Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.

Characterizing half-a-degree difference: a review of methods for identifying regional climate responses to global warming targets

Abstract: The Paris Agreement long-term global temperature goal refers to two global warming levels: well below 2°C and 1.5°C above preindustrial. Regional climate signals at specific global warming levels, and especially the differences between 1.5°C and 2°C, are not well constrained, however. In particular, methodological challenges related to the assessment of such differences have received limited attention. This article reviews alternative approaches for identifying regional climate signals associated with global temperature limits, and evaluates the extent to which they constitute a sound basis for impacts analysis. Four methods are outlined, including comparing data from different greenhouse gas scenarios, sub-selecting climate models based on global temperature response, pattern scaling, and extracting anomalies at the time of each global temperature increment. These methods have rarely been applied to compare 2°C with 1.5°C, but some demonstrate potential avenues for useful research. Nevertheless, there are methodological challenges associated with the use of existing climate model experiments, which are generally designed to model responses to different levels of greenhouse gas forcing, rather than to model climate responses to a specific level of forcing that targets a given level of global temperature change. Novel approaches may be required to address policy questions, in particular: to differentiate between half degree warming increments while accounting for different sources of uncertainty; to examine mechanisms of regional climate change including the potential for nonlinear responses; and to explore the relevance of time-lagged processes in the climate system and declining emissions, and the resulting sensitivity to alternative mitigation pathways.

History, Path Dependence and Development: Evidence from Colonial Railways, Settlers and Cities in Kenya

Abstract: Little is known about the extent and forces of path dependence in developing countries. Colonial era railroad construction in Kenya provides a natural experiment to study the emergence and persistence of spatial equilibrium. Data spanning over one century shows that railroads determined the location of European settlers, Asian traders, and the main cities at independence. Europeans then left, Asians departed, and railroads declined in the immediate post-independence period, constituting local shocks to physical and human capital. Yet the colonial cities persisted. We test four explanations for path dependence based on institutional persistence, technological change, sunk investments, and spatial coordination failures.

Who Becomes an Inventor in America? The Importance of Exposure to Innovation

Abstract: We characterize the factors that determine who becomes an inventor in America by using de-identified data on 1.2 million inventors from patent records linked to tax records. We establish three sets of results. First, children from high-income (top 1%) families are ten times as likely to become inventors as those from below-median income families. There are similarly large gaps by race and gender. Differences in innate ability, as measured by test scores in early childhood, explain relatively little of these gaps. Second, exposure to innovation during childhood has significant causal effects on children's propensities to become inventors. Growing up in a neighborhood or family with a high innovation rate in a specific technology class leads to a higher probability of patenting in exactly the same technology class. These exposure effects are gender-specific: girls are more likely to become inventors in a particular technology class if they grow up in an area with more female inventors in that technology class. Third, the financial returns to inventions are extremely skewed and highly correlated with their scientific impact, as measured by citations. Consistent with the importance of exposure effects and contrary to standard models of career selection, women and disadvantaged youth are as under-represented among high-impact inventors as they are among inventors as a whole. We develop a simple model of inventors' careers that matches these empirical results. The model implies that increasing exposure to innovation in childhood may have larger impacts on innovation than increasing the financial incentives to innovate, for instance by reducing tax rates. In particular, there are many "lost Einsteins" - individuals who would have had highly impactful inventions had they been exposed to innovation.