Public goods in networks

This paper considers incentives to provide goods that are non-excludable along social or geographic links. We find, first, that networks can lead to specialization in public good provision. In every social network there is an equilibrium where some individuals contribute and others free ride. In many networks, this extreme is the only outcome. Second, specialization can benefit society as a whole. This outcome arises when contributors are linked, collectively, to many agents. Finally, a new link increases access to public goods, but reduces individual incentives to contribute. Hence, overall welfare can be higher when there are holes in a network.     

Wage inequality, technology, and trade

The recent widening of wage inequality has been attributed by some to skill-biased-technical-change and by others to trade liberalization. This paper examines the two explanations within a unified model and also presents a new modeling of skill-biased-technical-change, where skilled workers replace unskilled ones. As a result technology adoption is endogenous and does not occur in all countries. Hence, wages for both types of workers, trade patterns and also factor productivities in all countries are endogenously determined. The model sheds light on the relationship between technology and trade, on the reasons for global productivity differences and on the causes for the recent rise in wage inequality.     

Education, Work and Wages in the UK

Abstract. This paper is concerned with the relationship between education, wages and working behaviour. The work is partly motivated by the sharp distinction in the literature between the returns to education and the effect of wages on labour supply. Education is the investment that cumulates in the form of human capital while labour supply is the utilization rate of that stock. Yet, variation in education is usually the basis for identifying labour supply models – education is assumed to determine wages but not affect labour supply. Moreover, it is commonly assumed that the private rate of return to education can be found from the schooling coefficient in a log-wage equation. Yet, the costs of education are largely independent of its subsequent utilization but the benefits will be higher the greater the utilization rate. Thus the returns will depend on how intensively that capital is utilized and we would expect that those who intend to work least to also invest least in human capital. Indeed, the net (of tax liabilities and welfare entitlements) return to education will be a complex function of labour supply and budget constraint considerations.
Here we attempt to model the relationship between wages, work, education and the tax/welfare system allowing for the endogeneity of education as well for the correlations between the unobservable components of wages and working behaviour. We use the estimates to simulate the effect of a new UK policy designed to increase education for children from low-income households.     

Experiencing change and the evolution of adaptive skills: Implications for economic growth

We distinguish learning in a static environment from that in a dynamic environment to show the existence of an important interaction between the development of new technologies and human capital accumulation. Because technological progress creates a more dynamic environment, it complements education in the production of human capital by enhancing adaptive skills. Higher levels of adaptability and human capital in turn determine the profitability of new inventions and the incentive to invest in new R&D. Differences in the history of technological progress produce different levels of adaptability and our results suggest why countries that have comparable levels of education and per capita incomes may differ significantly in their growth performance.     

Education, segregation and marital sorting: theory and an application to the UK

This paper presents a model of the intergenerational transmission of education and marital sorting. Parents matter both because of their household income and because their human capital determines the distribution of a child's disutility from making an effort to become skilled. We show that an increase in segregation has potentially ambiguous effects on the proportion of individuals that become skilled in the steady state, and hence on marital sorting, the personal and household income distribution, and welfare. We calibrate the steady state of our model to UK statistics. We find that an increase in the correlation of spouses in their years of education will bring about a small increase in the proportion of skilled individuals when the relative supply of skilled individuals is variable at the family level and a decrease when this supply is fixed. Ex-ante utility (of an unborn individual) increases in the first case and decreases in the second. The welfare effect of increased sorting is negative for unskilled individuals and positive for skilled individuals. Increased segregation always leads to an increase in welfare inequality between skilled and unskilled individuals.     

Contest architecture

A contest architecture specifies how the contestants are split among several sub-contests whose winners compete against each other (while other players are eliminated). We compare the performance of such dynamic schemes to that of static winner-take-all contests from the point of view of a designer who maximizes either the expected total effort or the expected highest effort. For the case of a linear cost of effort, our main results are: (1) If the designer maximizes expected total effort, the optimal architecture is a single grand static contest. (2) If the designer maximizes the expected highest effort, and if there are sufficiently many competitors, it is optimal to split the competitors in two divisions, and to have a final among the two divisional winners. Finally, if the effort cost functions are convex, the designer may benefit by splitting the contestants into several sub-contests, or by awarding prizes to all finalists.     

Trade unions vs. statistical discrimination: Theory and application to post-apartheid South Africa

A simple model of statistical discrimination is analyzed, which captures some stylized facts of the South African labor market. It shows that this type of discrimination disappears when the wage rates are determined by efficient bargaining between a representative firm and a union, with endogenous membership. This may explain why the wage gap between Black and White workers in post-apartheid South Africa is smaller among unionized workers than among non-unionized ones.     

External wealth, the trade balance, and the real exchange rate

We examine the link between the net foreign asset position, the trade balance and the real exchange rate. In particular, we decompose the impact of a country's net foreign asset position (‘external wealth’) on its long-run real exchange rate into two mechanisms: the relation between external wealth and the trade balance; and, holding fixed other determinants, a negative relation between the trade balance and the real exchange rate. We also provide additional evidence that the relative price of nontradables is an important channel linking the trade balance and the real exchange rate.     

中国各地区集约经济运营绩效的DEA评价

DEA方法是进行相对有效性评价的一种方法。其最先提出并被广泛应用的C2R模型可同时判断决策单元是否同时满足技术有效和规模有效。通过利用DEA模型对我国30个地区的集约经营效率进行了分析评价,并探讨了制约我国各地区集约经济发展的重要因素及其对策问题。     

Tax Competition, Capital Mobility and Innovation in the Public Sector

Abstract. The paper analyses the impact of tax competition on innovation in the public sector. It is shown that the effects of increased mobility of the tax base on innovation and growth are ambiguous. The negative relationship is more likely, however. Moreover, it is shown that a Leviathan government may be induced to spend a larger share of its budget on unproductive activities.