Towards an integrated scientific and social case for human space exploration

I will argue that an ambitious programme of human space exploration, involving a return to the Moon, and eventually human missions to Mars, will add greatly to human knowledge. Gathering such knowledge is the primary aim of science, but science's compart-mentalisation into isolated academic disciplines tends to obscure the overall strength of the scientific case. Any consideration of the scientific arguments for human space exploration must therefore take a holistic view, and integrate the potential benefits over the entire spectrum of human knowledge. Moreover, science is only one thread in a much larger overall case for human space exploration. Other threads include economic, industrial, educational, geopolitical and cultural benefits. Any responsibly formulated public space policy must weigh all of these factors before deciding whether or not an investment in human space activities is scientifically and socially desirable

A nonparametric test of stochastic dominance in multivariate distributions

The literature on statistical test of stochastic dominance has thus far been concerned with univariate distributions. This paper presents nonparametric statistical tests for multivariate distributions. This allows a nonparametric treatment of multiple welfare indicators. These test are applied to a time series of cross-section datasets on household level total expenditure and non labour market time in the UK. This contrasts the welfare inferences which might be drawn from looking at univariate (marginal) distributions with those which consider the joint distribution.Social welfare, stochastic dominance, nonparametric statistical methods

A nonparametric analysis of habits models

This paper presents a nonparametric analysis of the canonical habits model. The approach is based on the combinatorial/revealed preference framework of Samuelson (1948), Houthakker (1950), Afriat (1967) and Varian (1982) and the extenstion and application of these ideas to intertemporal models in Browning (1989). It provides a simple finitely computable test of the model which does not require a parameterisation of the underlying (hypothesised) preferences.It also yields set identification of important features of the canonical habits model including the consumer's rate of time preference and the welfare effects of habit-formation. The ideas presented are illustrated using Spanish panel data.

Variations in the price of foods and nutrients in the UK

This paper investigates the patterns and extent of differences in the prices paid for foods, and for the nutrients they contain, amongst households in the UK. The data used are from the National Food Survey and are unit prices, quantities purchased and nutrient conversion factors for each food. The paper first describes the circumstances under which ratios of unit prices are exact measures of cross section price variation. It also discusses a nonparametric method of recovering the underlying prices of nutrients under the maintined assumption that households have rational preferences over the nutritional characteristics of foods. It then uses these data to describe patterns in the variation of the price of food and nutrients with repect to household and regional characteristics.

Necessary and Sufficient Conditions for Latent Separability

This paper extends the nonparametric methods developed by Samuelson (1948), Houthakker (1950), Afriat (1973), Diewert (1973) and Varian (1982, 1983) to latently separable models. It presents necessary and sufficient empirical conditions under which data on the market behaviour of a price-taking consumer, and a hypothesised allocation across latent groups are nonparametrically consistent with latent separability (Gorman (1968, 1978), Blundell and Robin (2000)). It considers homothetic latent separability and weak separability as special cases.Separability, revelaed preference

UK household cost-of-living indices, 1979-92

The only circumstance under which one can speak accurately about the cost-of-living index is one in which household expenditure patterns do not vary. If relative prices move and households consume goods and services in different proportions, then each household will have its own unique cost-of-living index. This paper is concerned with the pattern and extent of these variations in the cost of living between different types of household.

Estimation of household demand systems with theoretically compatible Engel curves and unit value specifications

We develop a method for estimation of price reactions using unit value data which exploits the implicit links between quantity and unit value choices. This allows us to combine appealing Engel curve specifications with a model of unit value determination in a way which is consistent with demand theory, unlike methods hitherto prominent in the literature. The method is applied to Czech data.Consumer demand, unit values

How demanding is the revealed preference approach to demand

A well known problem with revealed preference methods is that when data are found to satisfy their restrictions it is hard to know whether this should be viewed as a triumph for economic theory, or a warning that these conditions are so undemanding that almost anything goes. This paper allows researchers to make this distinction. Our approach builds on theoretical support in the form of an axiomatic cardinal characterisation of a measure of predictive success due to Selten(1991). We illustrate the idea using a large, nationally representative panel survey of Spanish consumers with broad commodity coverage. The results show that this approach to revealed preference methods can lead us radically to reassess our view of the empirical performance of economic theory.