Richard Spady (Official Fellow) spent the year primarily on two disparate topics, efficient semiparametric estimation of moment condition models, and microeconometric modelling of the UK supermarket industry. The work in semiparametric estimation (undertaken in collaboration with A Chesher (Bristol), A Davison (Oxford), and G Imbens (Harvard)), is aimed at unifying and improving a variety of methods used in econometrics to estimate parameters and test hypotheses in models which only specify that certain averages (expressible as functions of data and parameters) will be zero. This sort of model is of special interest in economics because economic theory does not often provide guidance that is more specific than such moment conditions. Consequently, these methods dispense with certain assumptions that are customarily made for convenience but are irrelevant to the theory under consideration.
The work on the UK supermarket industry (undertaken with H Smith, IES, Oxford) models household choice of supermarket and spending behaviour using two basic data sources. The first source provides information at the postal sector level concerning fascia choice (e.g. Tesco) and household characteristics. The second source provides the location and characteristics of every supermarket in Britain, as well as recent supermarket closures and planning permission denials. The goal of the analysis is to generate for each store an estimate of revenues, profitability, etc., and to address issues of competition and planning policy, e.g. whether the observed geographical distribution of fascias is compatible with competitive behaviour on the part of firms and whether planning policy has a demonstrable effect on supermarket prices.
Richard Spady gave seminars at the Universities of Birmingham, Carlos III (Madrid), Illinois (Urbana-Champaign), Iowa, Michigan (Ann Arbor), and Oxford (in the Department of Statistics), and also the Tinbergen Institute (Amsterdam). He has been Investment Bursar since July 1995.