Research Policy and U.S. Economic Growth

This paper examines quantitatively the effects of R&D subsidy and government-financed basic research on U.S. economic growth and consumer welfare. To achieve this, we develop an endogenous growth model which takes into account both public and private research investment, and the differences between basic and non-basic research. A calibrated version of the model is able to replicate some important features of the U.S. economy over the period 1953-2009. Our model suggests that government spending on basic research is an effective policy instrument to promote economic growth. Subsidizing private R&D, on the other hand, has no effect on economic growth

Fall-related attendance and associated hospitalisation of children and adolescents in Hong Kong: a 12-year retrospective study

Objectives: The present study aimed to examine the trends and characteristics of fall-related attendance in accident and emergency department (AED) by injury type and the trend in associated average length of stay (LOS) among children and adolescents in Hong Kong. Design: A retrospective approach was adopted. Setting: AED, involving all local public emergency departments from 2001 to 2012. Participants: 63 557 subjects aged 0–19 years with fall injury record were included in the analysis. Primary outcome measures: Fall-related injury number and rates were calculated and reported. Poisson and negative binomial regression models were used to study the trends of injury incidence rate at different body regions. Results: AED fall-related attendance rate increased significantly with an annual percentage change of 4.45 (95% CI 3.43 to 5.47%, p<0.0001). The attendance number of male subjects was persistently higher than female subjects. The standardised rate of fracture injury increased by 1.31% (95% CI 0.56 to 2.05%, p<0.0001) and that of non-fracture injury increased by 9.23% (95% CI 7.07 to 11.43%, p<0.0001) annually. Upper limb was the most frequently fractured location. It included forearm/elbow, shoulder/upper arm and wrist/hand with descending order of frequency. On the contrary, head was the most frequent non-fracture location, followed by forearm/elbow. Conclusions: The rates of fall-related attendance have been increasing and still remain high. There were significant increases in non-fracture injuries. Fractures were most frequently found in the upper extremity of a child while the most common non-fracture location was head. It appears that more efforts should be made and preventive measures should be implemented for children and adolescents in Hong Kong

Physical activity, sedentary time and breast cancer risk: a Mendelian randomisation study

Objectives: Physical inactivity and sedentary behaviour are associated with higher breast cancer risk in observational studies, but ascribing causality is difficult. Mendelian randomisation (MR) assesses causality by simulating randomised trial groups using genotype. We assessed whether lifelong physical activity or sedentary time, assessed using genotype, may be causally associated with breast cancer risk overall, pre/post-menopause, and by case-groups defined by tumour characteristics. Methods: We performed two-sample inverse-variance-weighted MR using individual-level Breast Cancer Association Consortium case-control data from 130 957 European-ancestry women (69 838 invasive cases), and published UK Biobank data (n=91 105–377 234). Genetic instruments were single nucleotide polymorphisms (SNPs) associated in UK Biobank with wrist-worn accelerometer-measured overall physical activity (nsnps=5) or sedentary time (nsnps=6), or accelerometer-measured (nsnps=1) or self-reported (nsnps=5) vigorous physical activity. Results: Greater genetically-predicted overall activity was associated with lower breast cancer overall risk (OR=0.59; 95% confidence interval (CI) 0.42 to 0.83 per-standard deviation (SD;~8 milligravities acceleration)) and for most case-groups. Genetically-predicted vigorous activity was associated with lower risk of pre/perimenopausal breast cancer (OR=0.62; 95% CI 0.45 to 0.87,≥3 vs. 0 self-reported days/week), with consistent estimates for most case-groups. Greater genetically-predicted sedentary time was associated with higher hormone-receptor-negative tumour risk (OR=1.77; 95% CI 1.07 to 2.92 per-SD (~7% time spent sedentary)), with elevated estimates for most case-groups. Results were robust to sensitivity analyses examining pleiotropy (including weighted-median-MR, MR-Egger). Conclusion: Our study provides strong evidence that greater overall physical activity, greater vigorous activity, and lower sedentary time are likely to reduce breast cancer risk. More widespread adoption of active lifestyles may reduce the burden from the most common cancer in women

On the Cause of Increased Longevity and Urban Sprawl: A Macroeconomic Approach

This dissertation can be divided into two parts. The first part is motivated by two trends that occurred during the second half of the twentieth century. First, there was a persistent rising trend in medical spending. Second, there was a significant increase in longevity. Chapter 1 presents a model in which a combination of technological progress in medical treatment and rising incomes can explain these two. The main theme of this chapter is that the rapid growth in health care spending was not driven by factors associated with market structures or insurance opportunities, but by factors underlying the production and accumulation of health, namely improvements in medical treatment and rising incomes. According to this model, these two factors can explain all of the increase in health care spending and more than 60% of the increase in life expectancy at age 25 during the period 1950-2001. The next question considered is whether or not it is efficient to allocate so many resources to the health care sector. To answer this question, a benchmark for welfare analysis is constructed in Chapter 2. This is then compared to the model presented in Chapter 1. An equivalent variation measure is used to quantify the welfare differences between the two. One major finding of the second chapter is that, with improvements in medical treatment and rising incomes, a large increase in medical spending can be obtained even in the first-best scenario. The second part of this dissertation is motivated by two other phenomena that happened over the period 1910-1970. First, a rising fraction of the urban population chose to live far away from the city center. Second, there was a significant increase in car-ownership. he objective of Chapter 3 is to assess quantitatively the relationship between the two. To achieve this, a simple model is constructed in which people can choose where to live and whether or not to purchase a car. The calibrated version of the model is able to explain about 86% of car-ownership in 1970 and about 77% of the suburbanization trend during the period 1910-1970.Technological Progress, Life Expectancy,Medical Spending, Automobiles, Suburbanization

Physical activity, sedentary time and breast cancer risk: a Mendelian randomisation study

Objectives Physical inactivity and sedentary behaviour are associated with higher breast cancer risk in observational studies, but ascribing causality is difficult. Mendelian randomisation (MR) assesses causality by simulating randomised trial groups using genotype. We assessed whether lifelong physical activity or sedentary time, assessed using genotype, may be causally associated with breast cancer risk overall, pre/post-menopause, and by case-groups defined by tumour characteristics.Methods We performed two-sample inverse-variance-weighted MR using individual-level Breast Cancer Association Consortium case-control data from 130 957 European-ancestry women (69 838 invasive cases), and published UK Biobank data (n=91 105-377 234). Genetic instruments were single nucleotide polymorphisms (SNPs) associated in UK Biobank with wrist-worn accelerometer-measured overall physical activity (n(snps)=5) or sedentary time (n(snps)=6), or accelerometer-measured (n(snps)=1) or self-reported (n(snps)=5) vigorous physical activity.Results Greater genetically-predicted overall activity was associated with lower breast cancer overall risk (OR=0.59; 95% confidence interval (CI) 0.42 to 0.83 per-standard deviation (SD;similar to 8 milligravities acceleration)) and for most case-groups. Genetically-predicted vigorous activity was associated with lower risk of pre/perimenopausal breast cancer (OR=0.62; 95% CI 0.45 to 0.87,>= 3 vs. 0 self-reported days/week), with consistent estimates for most case-groups. Greater genetically-predicted sedentary time was associated with higher hormone-receptor-negative tumour risk (OR=1.77; 95% CI 1.07 to 2.92 per-SD (similar to 7% time spent sedentary)), with elevated estimates for most case-groups. Results were robust to sensitivity analyses examining pleiotropy (including weighted-median-MR, MR-Egger).Conclusion Our study provides strong evidence that greater overall physical activity, greater vigorous activity, and lower sedentary time are likely to reduce breast cancer risk. More widespread adoption of active lifestyles may reduce the burden from the most common cancer in women.Genome Instability and Cance