基于古诺模型的四种市场的社会福利

市场根据垄断程度的不同。可以分为完全竞争、垄断竞争、寡头垄断和完全垄断市场四种类型。基于古诺模型，用博弈论方法研究n个厂商市场情形的总产量、价格、总收益和消费者剩余并把它们归纳为统一的公式。从四种市场情形总产量和价格的特点推出其供给曲线的形状，进而比较其社会福利的状况。研究结果表明，随着垄断性的加强，市场的社会福利会越来越劣，完全竞争市场的社会福利最好，垄断竞争市场次之，寡头垄断市场更次，完全垄断市场的社会福利最差。     

On equitable social welfare functions satisfying the Weak Pareto Axiom: A complete characterization

The present paper examines the problem of aggregating infinite utility streams with a social welfare function that respects the Anonymity and Weak Pareto Axioms. The paper provides a complete characterization of domains (of the one period utilities) on which such an aggregation is possible. A social welfare function satisfying the Anonymity and Weak Pareto Axioms exists on precisely those domains that do not contain any set of the order type of the set of positive and negative integers. The criterion is applied to decide on possibility and impossibility results for a variety of domains. It is also used to provide an alternative formulation of the characterization result in terms of the accumulation points of the domain.     

经济增长与环境

在政府不参与环境控制时,经济增长率最高,但污染也最严重,社会福利要比政府采取补贴情形时低.通过建立模型推导出了在放任政策下的经济增长率是最快的,但污染比较严重。     

扩大居民消费需求的重点、难点及对策——基于河北的调查

以河北省城乡居民消费需求调查情况为依据,分析了城乡居民的家庭月平均收支、居民消费意愿和消费环境,提出了扩大城乡居民消费需求的对策建议。     

Rising Food Prices and Household Welfare: Evidence from Brazil in 2008

Food price inflation in Brazil in the 12 months to June 2008 was 18%, whereas overall inflation was 7%. Using spatially disaggregated monthly data on consumer prices and two different household surveys, we estimate the welfare consequences of these food price increases, and their distribution across households. Because Brazil is a large food producer, with a predominantly wage‐earning agricultural labour force, our estimates include general equilibrium effects on market and transfer incomes, as well as the standard estimates of changes in consumer surplus. Although the expenditure (or consumer surplus) effects were large, negative and markedly regressive everywhere, estimates of the market‐income effect were positive and progressive, particularly in rural areas. Because of this effect on the rural poor, and of the partial protection afforded by increases in two large social assistance benefits, the overall impact of higher food prices in Brazil was U‐shaped, with middle‐income groups suffering larger proportional losses than the very poor. Nevertheless, as Brazil is 80% urban, higher food prices still led to a greater incidence and depth of poverty at the national level.     

Local impacts of a global crisis: Food price transmission,consumer welfare and poverty in Ghana

This paper takes a local perspective on global food price shocks by analyzing food price transmission between regional markets in Ghana. It also assesses the impacts of food price increases on various household groups. Taking the 2007–2008 global food crisis as an example, we show that prices for domestic grain products are highly correlated with world market prices. This is true both for products for which Ghana is highly import-dependent (e.g., rice) and the products for which Ghana is self-sufficient (e.g., maize). The econometric results also show that price transmission is high between regional producer markets and markets located in the country’s largest cities, and the distance between producer and consumer markets and the size of consumer markets matter in explaining the price transmission. The welfare analysis for households as consumers shows that the effect of world food prices appears relatively modest for the country as a whole due to relatively diverse consumption patterns within country. However, the national average hides important regional differences, both between regions and within different income groups. We find that the poorest of the poor—particularly those living in the urban areas—are hardest hit by high food prices. The negative effect of the food crisis is particularly strong in northern Ghana. The main explanations for this regional variation in the price effect is the different consumption patterns and much lower per capita income levels in the North of Ghana compared to other regions in the country.     

Assessing the Fiscal Costs and Benefits of A8 Migration to the UK*

This paper assesses the fiscal consequences of migration to the UK from the Central and Eastern European countries that joined the European Union in May 2004 (A8 countries). We show that A8 immigrants who arrived after EU enlargement in 2004 and who have at least one year of residence, and are therefore legally eligible to claim benefits, are 59 per cent less likely than natives to receive state benefits or tax credits and 57 per cent less likely to live in social housing. Furthermore, even if A8 immigrants had the same demographic characteristics as natives, they would still be 13 per cent less likely to receive benefits and 29 per cent less likely to live in social housing. We go on to compare the net fiscal contribution of A8 immigrants with that of individuals born in the UK, and find that in each fiscal year since enlargement in 2004, irrespective of the way that the net fiscal contribution is defined, A8 immigrants made a positive contribution to the public finances despite the fact that the UK has been running a budget deficit over the last few years. This is because they have a higher labour force participation rate, pay proportionately more in indirect taxes and make much less use of benefits and public services.     

THE IMPACT OF ANTI‐TERRORISM EXPENDITURE ON ECONOMIC GROWTH AND WELFARE

This paper examines the effects of increasing anti‐terrorism expenditure on economic growth rate and social welfare. It is shown that: (i) spending the least amount possible on anti‐terrorism expenditure will lead to a maximum economic growth rate; and (ii) to achieve maximum social welfare, the government should allocate its budget to anti‐terrorism expenditure. The results shed light on why the US government has chosen to uphold and pursue its anti‐terrorism policies in recent years to present day.     

Social Interaction Effects in Disability Pension Participation: Evidence from Plant Downsizing*

We estimate the magnitude of social interaction effects in disability pension participation among older workers in Norway. The problem of omitted variable bias is addressed using the exposure of an individual's neighbors to plant‐downsizing events as an instrument for the disability entry rate among the individual's previously employed neighbors. Our instrumental variable (IV) estimates suggest that an increase of one percentage point in the participation rate of previously employed neighbors increased the subsequent four‐year entry rate of older workers by about 0.4 percentage points. Numerous robustness and specification tests appear to support the validity of the identifying assumption in our IV strategy.