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1.
We consider here a management policy for a sika deer (Cervus nippon) population in the eastern part of Hokkaido. Deer populations are characterized by a large intrinsic rate of population increase, no significant density effects on population growth before population crash, and a relatively simple life history. Our goals of management for the deer population are (1) to avoid irruption with severe damage to agriculture and forestry, (2) to avoid the risk of extinction of the deer population, and (3) to maintain a sustainable yield of deer. To make a robust program on the basis of uncertain information about the deer population, we consider three levels of relative population size and four levels of hunting pressures. We also take into consideration a critical level for extinction, an optimal level, and an irruption level. The hunting pressure for females is set to increase with the population size. We also recommend catching males if the population size is between the critical and optimal levels and catching females and males if the population size is larger than the optimal level. We must avoid cases of irruption or threatened population under various sets of uncertain parameter values. The simulation results suggest that management based on sex-specific hunting is effective to diminish the annual variation in hunting yield. Received: April 8, 1998 / Accepted: December 25, 1998  相似文献   

2.
In this paper, we examine the optimal pay-as-you-go social security scheme which reallocates resources across generations in a changing environment, that is, with fluctuations in population growth rates and in productivity levels. We use an overlapping generations model along with a social welfare function consisting of the sum of generational utilities either unweighted or weighted by population size and a discount factor. We show how intergenerational resource sharing can be used to improve social welfare even though the extent of intergenerational redistribution is hampered by payroll tax deadweight losses in the spirit of the optimal taxation literature. Also it appears that resource sharing is much more restricted in a closed economy that in an open economy, which is not subject to a national resource constraint at each period of time. This paper was presented at the 1990 ISPE-Conference on the Fiscal Implications of an Ageing Population, Vaalsbroek Castle, Netherlands. The authors wish to thank the participants and particularly B. van Praag and W. Peters for their comments. They also thank the two referees and Philippe Michel for very helpful comments and discussions. The financial support of CIM during his sabbatical year is greatly acknowledged by the second author.  相似文献   

3.
The purpose of this paper is to study intergenerational optimal resources sharing when the social planer can choose the retirement age in addition to consumptions and investment. We use the extension of the Diamond analysis by Hu [1979] that incorporates endogenous retirement age. We found that the optimal retirement age is an increasing function of the population growth rate if the elasticity of substitution of old agents' labor for young agents' labor is lower than one. In the millian case, when the size of a population does not matter, and when the elasticity of substitution of old agents' labor for young agents' labor is strictly higher than one, the optimal retirement age is a decreasing function of the population growth rate. In the benthamite case, the change in the optimal retirement age is indeterminate. Received: 19 February 1999/Accepted: 27 February 2001 All correspondence to Bertrand Crettez. We would like to thank Jean-Pierre Vidal for very helpful comments on an earlier draft. An anonymous referee provided insightful comments on a previous version of this paper. Responsible editor: Alessandro Cigno.  相似文献   

4.
In recent years, many studies have focused on the body of sexual minority women, particularly emphasizing their larger size. These studies rarely offer theoretically based explanations for the increased weight, nor study the potential consequences (or lack thereof) of being heavier. This article provides a brief overview of the multitude of factors that might cause or contribute to larger size of sexual minority women, using an ecological framework that elucidates upstream social determinants of health as well as individual risk factors. This model is infused with a minority stress model, which hypothesizes excess strain resulting from the stigma associated with oppressed minority identities such as woman, lesbian, bisexual, woman of color, and others. We argue that lack of attention to the upstream social determinants of health may result in individual-level victim blaming and interventions that do not address the root causes of minority stress or increased weight.  相似文献   

5.
It is significant in China, as the day of 5 billion is commemorated, that the Government has shown its full committment to a family planning program that has been internationally acknowledged as one of the most successful efforts in the world today. Since 1979, the annual population growth rate in China has gone down from 2.7% to an annual average of around 1.2%. In fact, because China makes up more than 1/5 of the world's population, the overall growth rate achieved worldwide has been reduced to about 2%. This is heavily due to the achievements of the Chinese family planning program. Even as China has lowered its birthrate, its rate of agricultural production has rapidly risen. At present, China is doing well in grain production. Although the per capita income in China is still comparatively low, the country is able to feed its citizens, and the famines that used to be a big problem are now but a bad memory. As the close relationship between population and development is observed, there is some controversy about the effects and impact of family planning on development. The belief is held that the more people there are in this world, the more progress there will be because more brains, hands, and energy will be harnessed for development. As has also been noted, however, a person is not just head and hands--a person has a mouth to feed, as well. Thus, there is a need to balance the number of people with the resources of the society. If the rate of population growth outstrips economic and social production, then hunger and poverty will result, as the fruits of development will be eaten up too rapidly.  相似文献   

6.
Abstract In demographic literature Java occupies a special position. It is the island where in the nineteenth century a 'population explosion' occurred. In other developing countries this took place in the twentieth century. Following the official figures Java had a population size of about 4.5 million in 1815 (Raffles's Census) and 28.5 million in 1900. The result is an extraordinary rate of growth of 2.2% per year. In this paper it is argued that it is impossible to correct the data by adjusting them. A more promising method is to study the factors which are responsible for the demographic situation, i.e. economic conditions, the so-called pax neerlandica and the health situation in the period 1800-1850. This period has been specially studied, because it is crucial for the calculation of population size which is normally based on the 1815 period. It is suggested that Java cannot really claim to be an exceptional case in the period 1800-1850. This means that the growth rate - in line with the estimates of Carr Saunders and Sauvy -has to be estimated (greater accuracy is not possible) as between 0.5% and 1.0); per annum. On the basis of estimates and calculations, the population size of Java may have been somewhere between 8 and 10 millions around 1800, the latter estimate being the more realistic figure. The view that there was exceptionally rapid population growth in Java in the nineteenth century is to an important degree the product of a Europe-centred approach to the history of Java.  相似文献   

7.
Aging, fertility, social security and political equilibrium   总被引:1,自引:1,他引:0  
We analyze the effect of population aging on the political choice of the size of a pay-as-you-go (PAYG) social security system, incorporating the heterogeneity of individuals in their preference for having children, and hence the endogenous fertility choices of individuals, into a simple overlapping generations model. We show that population aging may result in an increase in the contribution rate, increasing the share of the retired population who prefer a higher contribution rate; and that, if the system involves redistribution between retirees with different contributions, the increased contribution rate raises the number of individuals who have children, i.e., future contributors.  相似文献   

8.
The old age security hypothesis and optimal population growth   总被引:2,自引:2,他引:0  
The old age security approach is used to study the relationship between the rate of growth of the population and capital accumulation, within a Samuelson-Diamond overlapping generations framework. It is shown that a decentralized economy will fail, in general, to achieve the Pareto optimal path. However, a pay-as-you-go social security scheme in which the old get transfers which are proportional to the number of their children may restore optimality. On the other hand, child support systems or subsidies to capital can guarantee the optimal capital: labor ratio, but not the optimal population growth rate, while a lump sum social security system can guarantee the optimal population growth rate, but not the optimal capital: labor ratio. Finally, in a monetary economy any policy aimed at correcting the interest rate will restore full optimality.An earlier version of this paper was written during a visit to the University of California, San Diego. The paper benefited from the comments of two referees.  相似文献   

9.
This essay deals with population growth, varieties in population density, and their impacts on social development from the viewpoint of Socialism. The author's main argument can be summarized as follows: 1) population growth is a kind of social production, and it is more important than the geographical environment in relation to social development. Regarding population growth, varieties in population density, and the geographical environment as conditions of equal importance in social life is debatable. 2) the changes in population development should not be limited to the changes in number alone. As science and technology are developed, the impact of changes of population quality on social development is becoming increasingly important. 3) population growth is not the major force which determines the social outlook and social system, and it directly influences social productivity. One should not think that a large population and rapid growth rate will speed up social productivity, or that a small population and a slow growth rate will slow down the development of social productivity. The author quotes Joseph Stalin to support his argument.  相似文献   

10.
In a general-equilibrium OLG model with endogenous longevity, a political economy and a social planner solution are contrasted mainly with respect to public supplies of health care and environment protection. The latter is relatively more supported by the young because its beneficial effect on longevity takes more time to occur but then lasts longer; while the old relatively prefer health spending. With population aging, political claims for health care expenditure are self-reinforcing. This framework is able to generate a quite rich set of results. In the political economy larger health care/consumption and health care/environmental quality ratios are implemented. Changes in risk aversion, production pollution, health inputs’ elasticity of substitution may have opposite impacts across regimes. More complete annuity markets improve welfare. Further comparative statics is analyzed.  相似文献   

11.
Utilitarian tradeoff between population growth and income growth   总被引:1,自引:1,他引:0  
Utilitarian social welfare functions were devised for a world with a fixed population. With endogenous population, Edgeworth conjectured that the Benthamite principle of maximizing total utility (classical utilitarianism) would lead to a larger population size and a lower standard of living than the Millian principle of maximizing per capita utility (average utilitarianism). One objection to the Benthamite criterion was that its application to a world with finite resources often implied large population size in conjunction with an embarrassingly low average standard of living. In a static environment with altruistic parents, this may not be warranted. In a growth situation, this criticism is even less likely to be supported. This paper extends the comparison of classical and average utilitarianism from a static to a dynamic and endogenously growing economy. Using a stylised endogenous growth framework, it confirms that the Benthamite population growth rate exceeds the Millian growth rate. In terms of the rate of growth of per capita income, the reverse is true. Having the standard of living often increasing under the Benthamite criterion, our results thereby depart significantly from the repugnant conclusion levelled against classical utilitarianism.We would like to thank an anonymous referee for helpful suggestions.  相似文献   

12.
As the age at marriage continues to rise in East and Southeast Asia, the fertility behavior of unmarried teenagers is receiving more attention from population policymakers. In addition to fertility reduction through family planning, Asian societies today consider population planning strategies in relation to national needs and social goals, including such matters as the population's growth rate, age structure, educational quality and skills. The number of single youth in Asia is growing much more rapidly than the total youth population. By the year 2010, for example, India is projected to have nearly 70 million single teenagers, aged 15-19, 188% more than in 1980. In many developing countries today, such as the Philippines and Korea, the rising age at marriage has combined with rapid urbanization, improved status for women, and more educational opportunity to alter both the behavioral norms of young people and the traditional means of social control over youth. Studies of contemporary adolescent sexuality have been conducted in 4 Asian countries. In the Philippines an overt independent youth homosexual culture was found to exist in urban and to some extent rural areas. In Thailand research revealed little conservative resistance to family planning or to contraceptives for young unmarried people. Surveys in Taiwan indicate that behavior related to dating and choice of spouse has become more liberal, and a survey in Hong Kong revealed a higher level of premarital sex and use of prostitutes among Chinese men than expected. Population policy perspectives that need to be considered in these changing times include: 1) issues of access to family planning services by unmarried people below the legal age of maturity; 2) the development of social institutions, such as exist in Thailand and the Philippines, to guide adolescents' behavior; 3) more extensive study of adolescent sexuality; 4) establishment of the scope of family policy.  相似文献   

13.
Parfit’s Repugnant Conclusion stipulates that under total utilitarianism, it might be optimal to choose increasing population size while consumption per capita goes to zero. We evaluate this claim within a canonical AK model with endogenous population size and a reduced form relationship between demographic and economic growth. First we characterize the optimal solution paths for any capital dilution function. Second, we prove that while the Repugnant Conclusion can never occur for realistic values of intertemporal substitution in the traditional linear dilution model, it does occur when population growth is linked to economic growth via an inverted U-shaped relationship.  相似文献   

14.
Examining the Impact of Demographic Factors on Air Pollution   总被引:9,自引:0,他引:9  
This study adds to the emerging literature examining empirically the link between population size, other demographic factors and pollution. We contribute by using more reliable estimation techniques and examine two air pollutants. By considering sulfur dioxide, we become the first study to explicitly examine the impact of demographic factors on a pollutant other than carbon dioxide at the cross-national level. We also take into account the urbanization rate and the average household size neglected by many prior cross-national econometric studies. For carbon dioxide emissions we find evidence that population increases are matched by proportional increases in emissions while a higher urbanization rate and lower average household size increase emissions. For sulfur dioxide emissions, we find a U-shaped relationship, with the population-emissions elasticity rising at higher population levels. Urbanization and average household size are not found to be significant determinants of sulfur dioxide emissions. For both pollutants, our results suggest that an increasing share of global emissions will be accounted for by developing countries. Implications for the environmental Kuznets curve literature are described and directions for further work identified.  相似文献   

15.
This paper presents a simple general equilibrium analysis of first best allocations in an economy where a consumption good is produced using labor. Production results in pollution, which is a public bad. Pollution abatement can be achieved either by restricting production or by using additional labor. We consider how the first best allocation and Pigouvian tax vary with population size. Consumers are unambiguously worse off when the population is larger, but not necessarily due to increased pollution. In fact, optimal policy on how pollution and labor should vary with population size is very sensitive to preferences and technology. The best response to an increase in population size might be either to increase or to decrease emissions and/or labor, depending on functional forms and parameters. However, given separable preferences and some convexity, the optimal emissions tax increases, and the first best level of per-capita consumption decreases with population size. The paper also considers the extent to which exogenous technical progress can overturn these conclusions. Received August 28, 1996 / Accepted January 27, 1997  相似文献   

16.
Within a population of the web-building spiderAgelena limbata, the weight of the first instar nymphs ranged from 1.187 to 6.559 mg. Both intraclutch and interclutch variation were recorded. The mean weights were different among clutches and the coefficients of variation within a clutch ranged from 3.3 to 29.2%. Variation in the nymphal weight was certainly derived from variation in the egg weight because there was a high correlation between the two weights. Factors affecting interclutch variation in nymphal weight were examined by multiple regression analysis. Nymphal weight was positively correlated with the body size and food conditions of female parents, and negatively correlated with the clutch size. Among these three factors, the food conditions of female parents had the largest apparent effect on the interclutch variation. The results suggest that females with larger body size and more food produce larger offspring, and that there is a trade-off between offspring size and clutch size. Heavier nymphs had larger body size (carapace width) and may have larger energy reserves. Heavier nymphs survived experimental starvation for a significantly longer period.  相似文献   

17.
本文首先分析了人口数量与经济发展相互作用机制,从环境承载力角度分析了一定数量的人口是经济发展的必要条件,而当社会生产力发展到在特定空间内相对稳定时,若不断增长的人口数量超过社会经济发展的需求与承受能力,这时经济发展就要受到人口增长的困扰。其次本论文运用Granger因果分析方法和协整技术研究了中国人口增长率与经济发展水平之间相互作用数量关系。结果为:在短期内,在5%的显著性水平下,人口增长率对经济发展水平没有显著影响,而经济发展水平却对人口增长率有显著影响;从长期看,人口增长率与经济发展水平之间具有显著的负相关关系。最后得出结论:只有控制人口增长(尤其是农村人口增长),才能促进经济发展;而只有促进经济发展,才能更好的控制人口增长,两者相辅相成。  相似文献   

18.
Despite the existence of a national family planning program that dates to 1965 Pakistan has not seen a reduction in the fertility rate. One of the poorest countries in the world, Pakistan has 1 of the highest population growth rates in the world at about 3.0% annually. For over 2 decades, the average woman in Pakistan has given birth to more than 6 children. At the current fertility rate, the country's current population of 120 million will increase to over 150 million by the year 2000, and it will increase to 280 million by 2020. And even if today every woman were to begin having only 2 children, the population would still reach 160 million before leveling off. But reducing fertility in Pakistan will prove difficult. One of the leading obstacles is the low status of women. Few women in Pakistan have advanced education or professional jobs. Only 1/4 of those women without education or who are not working have any knowledge concerning contraception. Family size and composition also fuel the high rate of fertility. On the average, women desire 5 children (the fact that women average more than 5 suggests an unmet need for contraception). And due to social, cultural, and economic conditions, Pakistanis generally prefer male offsprings. Islamic opposition to family planning has also contributed to the continued high rates of fertility. Finally, administrative and management weaknesses have hindered Pakistan's family planning program. In order to overcome these obstacles, Pakistan will have to enlist the commitment of political, religious, and community leaders. The status of women will have to be improved, and the attitudes of people will need to change.  相似文献   

19.
中国妇女生育水平变动考证和未来人口发展的策略选择   总被引:6,自引:5,他引:1  
1990年以来各类人口调查和相关学者的研究结果显示,目前的低生育水平的实现有外在政策强力的作用,更有中国社会经济发展内生化的作用;真实的生育水平既不是调查包括人口普查所显示的那样低(低于1.5),也不是有关部门和政府所想象的那样高。调查显示农村居民平均生育意愿不会高于2个孩子,这是生育率持续稳定的根本。众所周知,为了保证人口稳定持续的发展,应使妇女生育率保持更替水平或至少接近更替水平。从人口发展规律和人口发展与社会经济发展相适应的规律出发,结合当前我国居民生育意愿和生育水平走低的实际,我们应该抓住生育政策调整的最佳时期,调整应该在最佳时期即未来5-10年内完成。  相似文献   

20.
There is a growing body of literature dealing with the causes behind anti-immigrant sentiment and xenophobia. Based on the literature on the fiscal burden model, this paper contends that the differences in attitudes toward immigration, between low and high statuses, can be explained by the size of the welfare state. We argue that the impact of socio-economic status on attitudes toward immigration is larger in countries where social expenditure is high. Since a potential increase in the number of welfare recipients due to new immigrants might lead to a reduction in per capita transfers, low-income individuals in these countries are expected to be more concerned about the effect of immigration on social benefits. Using multilevel models and data from the European Social Survey we have found that while the effect of socio-economic status on attitudes toward immigration is positive there is a great deal of variation between countries. The difference in attitudes between high and low socio-economic statuses increases as social expenditure increases. Moreover, increases of social expenditure in the short run increases anti-immigrant sentiment as it raises concerns about the impact of immigration on welfare services.  相似文献   

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