EFFECT OF GROUPING OF DATA ON THE DIVERGENCE BETWEEN LASPEYRES AND PAASCHE FORMS OF QUANTUM INDEXES*

Historical data for the manufacturing industry in the United States and United Kingdom are quoted, showing in most cases divergences between Laspeyres and Paasche forms of the quantum index that are by no means negligible. When the Paasche index for two of the series is recalculated with quantity indicators for industries instead of for products, the divergence is greatly reduced, and when quantity indicators for industry groups are substituted it almost disappears. This raises some questions about the practices of econometricians and statisticians, which are discussed. In a mathematical appendix by E. R. Coleman it is suggested that the grouping effect referred to does not depend on the particular way in which the data are grouped in most quantum indexes.     

Network externalities and long-run market shares

We study a dynamic duopoly model with network externalities. The value of the product depends on the current and past network size. We compare the market outcome to a planner. With equal quality products, the market outcome may result in too little standardization (i.e. too many products active in the long run) but never too much. The potential inefficiency is non-monotonic in the strength of the network effect, being most likely for intermediate levels. When products differ in quality, an inferior product may dominate even when the planner would choose otherwise, but only if the discount factor is sufficiently large     

Sectoral Energy- and Labour-Productivity Convergence

This paper empirically investigates the development of cross-country differences in energy- and labour productivity. The analysis is performed at a detailed sectoral level for 14 OECD countries, covering the period 1970–1997. A σ-convergence analysis reveals that the development over time of the cross-country variation in productivity performance differs across sectors as well as across different levels of aggregation. Both patterns of convergence as well as divergence are found. Cross-country variation of productivity levels is typically larger for energy than for labour. A β-convergence analysis provides support for the hypothesis that in most sectors lagging countries tend to catch up with technological leaders, in particular in terms of energy productivity. Moreover, the results show that convergence is conditional, meaning that productivity levels converge to country-specific steady states. Energy prices and wages are shown to positively affect energy- and labour-productivity growth, respectively. We also find evidence for the importance of economies of scale, whereas the investment share, openness and specialization play only a modest role in explaining cross-country variation in energy- and labour-productivity growth.      

Immigration: then,now, and in the future

The author examines recent changes in immigration flows to the United States. Consideration is given to the increase in Caribbean, Chinese, Indian, and Muslim immigration, which he attributes to today's lower costs of air travel. The negative impact of the ability to return home easily and cheaply on migrants' desire to fully acculturate into U.S. society is noted. Mention is made of the need for new international migration policies to meet the needs of guest workers and consultants.     

Erratic monetary policy and price variability

This paper examines the effect of erratic monetary policy on individual behavior, as well as the aggregate economy. It is demonstrated that an increase in erratic monetary policy causes an increase in demand for inventories by individuals. This behavior by individuals in turn leads to a higher variability of the price level, as well as a higher price level in the steady state of the aggregate economy.     

Wage inflation and labour conflicts in the Netherlands : An empirical investigation using the co-integration approach

The ‘wage space’, which is defined as the sum of price inflation and labour productivity growth, has played a major role as an indicator of allowable wage increases in the post-war wage negotiations in the Netherlands. This paper shows that: (a) wages and the wage space are co-integrated; (b) the deviation between wages and the wage space may act as an error correction term in the wage equation when both variables are identified as I(2); and (c) political consensus and the threat of labour conflicts (rather than actual strike activity) may be identified as the ‘mechanism’ behind this error correction in the wage equation.     

Uncertainty and sustainability in the management of rangelands

We analyze a dynamic and stochastic ecological-economic model of grazing management in semi-arid rangelands. The ecosystem is driven by stochastic precipitation. A risk averse farmer chooses a grazing management strategy under uncertainty such as to maximize expected utility from farming income. Grazing management strategies are rules about which share of the rangeland is given rest depending on the actual rainfall in that year. In a first step we determine a myopic farmer's optimal grazing management strategy and show that a risk averse farmer chooses a strategy such as to obtain insurance from the ecosystem: the optimal strategy reduces income variability, but yields less mean income than possible. In a second step we analyze the long-run ecological and economic impact of different strategies. We conclude that a myopic farmer, if he is sufficiently risk averse, will choose a sustainable grazing management strategy, even if he does not take into account long-term ecological and economic benefits of conservative strategies.     

DO PARENTAL INVOLVEMENT LAWS REDUCE ADOLESCENT ABORTION RATES?

This study assesses the impact of parental involvement laws on adolescent abortion rates and pregnancy rates. The analysis estimates abortion rate and pregnancy rate models using state-level data pooled over time for adolescents aged 15–17 compared to older teens aged 18–19 and adults aged 20–44. The results indicate that parental involvement laws reduce adolescent abortion rates and may, to a lessor degree, reduce adolescent pregnancy rates. Thus, the findings imply that enforcement of parental involvement laws will increase adolescent fertility rates.