健康、财富和福利

在更加宽泛的视角下，新证据揭示出较高的健康水平可以带来可观的经济回报     

Optimal Retirement with Increasing Longevity

We develop an optimizing life‐cycle model of retirement with perfect capital markets. We show that longer healthy life expectancy usually leads to later retirement, but with an elasticity less than unity. We calibrate our model using data from the US and find that, over the last century, the effect of rising incomes, which promote early retirement, has dominated the effect of rising lifespans. Our model predicts continuing declines in the optimal retirement age, despite rising life expectancy, provided the rate of real wage growth remains as high as in the last century.     

Demographic change, social security systems, and savings

In theory, improvements in healthy life expectancy should generate increases in the average age of retirement, with little effect on savings rates. In many countries, however, retirement incentives in social security programs prevent retirement ages from keeping pace with changes in life expectancy, leading to an increased need for life-cycle savings. Analyzing a cross-country panel of macroeconomic data, we find that increased longevity raises aggregate savings rates in countries with universal pension coverage and retirement incentives, though the effect disappears in countries with pay-as-you-go systems and high replacement rates.     

Geography,demography, and economic growth in Africa

This paper presents the effects of climate, topography, and natural ecology on public health, nutrition, demographics, technological diffusion, international trade and other determinants of economic development in Africa. The goal of this paper is to emphasize the need for intensified research on the issues at the intersection of ecology and human society. Geography was given emphasis because of three reasons: the minimal gain from another recitation of the damage caused by statism, protectionism and corruption to African economic performance; negligence of the role of natural forces in shaping economic performance; and tailoring of policies to geographical realities. The paper also discusses the general problems of tropical development and the focus of Africa's problems in worldwide tropical perspectives; demographic trends in Africa; use of standard cross-country growth equations with demographic and geographic variables, to account for the relative roles of geography; and the future growth strategies and the need for urban-based export growth in manufacturing and services. Lastly, the authors provide a summary of conclusions and discuss the agenda for future research.     

Longevity and Life‐cycle Savings*

We add health and longevity to a standard model of life‐cycle saving and show that, under plausible assumptions, increases in life expectancy lead to higher savings rates at every age, even when retirement is endogenous. In a stationary population these higher savings rates are offset by increased old age dependency, but during the disequilibrium phase, when longevity is rising, the effect on aggregate savings rates can be substantial. We find empirical support for this effect using a cross‐country panel of national savings rates.     

Have R&D Spillovers Declined in the 21st Century?

Slow growth over the last decade has prompted policy attention towards increasing R&D spending, often via the tax system. We examine the impact of R&D on firm performance, both by the firm's own investments and through positive (and negative) spillovers from other firms. We analyse panel data on US firms over the last three decades, and allow for time‐varying spillovers in both technology space (knowledge spillover) and product market space (product market rivalry). We show that the magnitude of R&D spillovers remains as large in the second decade of the 21^st century as it was in the mid 1980s. Since the ratio of the social return to the private return to R&D is about four to one, this implies that there remains a strong case for public support of R&D. Positive spillovers appeared to temporarily increase in the 1995–2004 digital technology boom. We also show how these micro estimates relate to estimates from the endogenous growth literature and give some suggestions for future work.     

Tourist market segmentation with linear and non-linear techniques

The need for in-depth knowledge of tourist market segments and the need to overcome the limitations of using linear techniques to analyse non-linear relationships requires a re-assessment of generally used approaches such as cluster analysis and multiple linear regression. The objectives of the research are (1) to consider the use of self-organising (SOM) neural networks for segmenting tourist markets and (2) to analyse the predictive ability of backpropagation (BP) neural networks for classifying tourists from follow-up surveys by using the output provided by a SOM neural network. The findings of the SOM neural network modelling indicate three natural clusters. In addition, the predictive ability of the BP neural network model appears to be superior to that of MLR static filter and logistic regression models. The BP neural network model developed for this application appears suitable for deployment (i.e. classification of tourists from follow-up surveys).     

Fertility, female labor force participation, and the demographic dividend

We estimate the effect of fertility on female labor force participation in a panel of countries using abortion legislation as an instrument for fertility. We find that removing legal restrictions on abortion significantly reduces fertility and estimate that, on average, a birth reduces a woman’s labor supply by almost 2 years during her reproductive life. Our results imply that behavioral change, in the form of increased female labor supply, contributes significantly to economic growth during the demographic transition when fertility declines.      

Assessing the value of short-term study abroad programmes to students

For many universities, students participating in short-term faculty-led programmes make up a large portion of the total study abroad population. In this article, we report the results of a unique choice experiment in which 1255 students were asked about their personal characteristics and their preferences for study abroad programme attributes. Using a random parameters logistic regression model, we find that students attitudes towards risk, their experience with international travel and their beliefs about whether study abroad would help them professionally were major determinants of whether a student expressed interest in studying abroad. We also estimate students’ willingness to pay for various programme attributes, including destination, programme duration, course type and the number of experiential learning activities. We find that the highest value programmes give students credit towards their major rather than towards the university core or as an elective and that they are 3–4 weeks in length rather than 2 or 6 weeks. Also, while students value more experiential learning activities per week, each additional trip adds less value with no additional value beyond four activities. Results are useful for practitioners interested in maximizing student participation while effectively managing study abroad budgets.     

Response to "The One-Way Mirror"

The variable, place attachment, has recently been used by investigators to assist in understanding visitor responses to fee programs on public lands. This paper examines the relationship between place attachment (i.e., place identity and place dependence), attitudes toward paying fees, and visitor preferences for spending fee revenue within the context of social judgment theory. It was hypothesized that both place dependence and place identity would moderate the relationship between recreationists' attitudes toward the site's fee program and visitor support for spending revenue generated by the fee program in the areas of facilities and service development, environmental protection, and environmental education. Data were collected at Mono Basin Scenic Area over the summer of 1998. Results indicated that only place identity was a statistically significant moderator, such that it magnified the relationship between recreationists' attitudes toward the fee program and spending support. As place identity increased and recreationists' attitudes toward the fee program became more positive, support for spending fee revenue also increased. Practical and theoretical implications are discussed.