On Conditional Density Estimation

With the aim of mitigating the possible problem of negativity in the estimation of the conditional density function, we introduce a so-called re-weighted Nadaraya-Watson (RNW) estimator. The proposed RNW estimator is constructed by a slight modification of the well-known Nadaraya-Watson smoother. With a detailed asymptotic analysis, we demonstrate that the RNW smoother preserves the superior large-sample bias property of the local linear smoother of the conditional density recently proposed in the literature. As a matter of independent statistical interest, the limit distribution of the RNW estimator is also derived.     

Further Evidence on PPP Adjustment Speeds: the Case of Effective Real Exchange Rates and the EMS*

Two different approaches intend to resolve the ‘puzzling’ slow convergence to purchasing power parity (PPP) reported in the literature [see Rogoff (1996) , Journal of Economic Literature, Vol. 34.] On the one hand, there are models that consider a non‐linear adjustment of real exchange rate to PPP induced by transaction costs. Such costs imply the presence of a certain transaction band where adjustment is too costly to be undertaken. On the other hand, there are models that relax the ‘classical’ PPP assumption of constant equilibrium real exchange rates. A prominent theory put together by Balassa (1964, Journal of Political Economy, Vol. 72) and Samuelson (1964 Review of Economics and Statistics, Vol. 46) , the BS effect, suggests that a non‐constant real exchange rate equilibrium is induced by different productivity growth rates between countries. This paper reconciles those two approaches by considering an exponential smooth transition‐in‐deviation non‐linear adjustment mechanism towards non‐constant equilibrium real exchange rates within the EMS (European Monetary System) and effective rates. The equilibrium is proxied, in a theoretically appealing manner, using deterministic trends and the relative price of non‐tradables to proxy for BS effects. The empirical results provide further support for the hypothesis that real exchange rates are well described by symmetric, nonlinear processes. Furthermore, the half‐life of shocks in such models is found to be dramatically shorter than that obtained in linear models.     

Demographic and Economic Pressure on Emigration out of Africa*

Two of the main forces driving European emigration in the late nineteenth century were real wage gaps between sending and receiving regions and demographic booms in the low‐wage sending regions. Our new estimates of net migration for the countries of sub‐Saharan Africa show that exactly the same forces driving African across‐border migration are at work today. The results suggest that rapid growth in the cohort of potential young emigrants, population pressure on the resource base, and slow economic growth are likely to intensify the pressure for migration out of Africa and into high‐wage OECD countries over the next two decades.     

The evolution of a local R&D strategy: the experience of a service in the UK National Health Service (NHS)

Increasing concern about the state of health‐related research in the UK in the 80s and early 90s, led to an influential parliamentary review. The consequence of this was to strengthen health research through a programme that was fully integrated into the management structure of the NHS. No country had ever attempted such an ambitious approach ( Black, 1997 ). In 1994 a far‐reaching review, recommended further, revolutionary changes to the management of R&D in the UK National Health Service ( Culyer, 1994 ). Many of these were implemented in 1997 with the result that every UK health service at regional and local level has developed an infrastructure, and management arrangements for R&D activity. In most local areas, hospitals with significant involvement in R&D have been eligible to bid to the UK Department of Health for NHS R&D Support funds. In Nottingham, three Hospital Trusts and a community based service made bids to the Department of Health and received grants to support R&D. This paper focuses on one of the hospital Trusts ‐ the mental health service in Nottingham. Our experience will be of particular interest as the first bid that the mental health service made was spectacularly unsuccessful. The organisation was forced to consider dis‐investment in its existing research infrastructure and a potential negative impact on the provision of patient care. This led to a wide‐ranging consultation and evaluation of research and research‐related activity. A range of approaches and tools were deployed to develop the strategy and to ensure its successful implementation and evolution. The strategy reflected a balanced approach, taking into account historical and organisational research strengths, while recognising the need to build capacity and capability, enhance foresight capability and strengthen the knowledge base. The ability to contribute to, and influence policy and practice has been a key driver of the strategy. The result was a successful bid and the evolution of an R&D strategy that has been flexible in its response to policy changes, changing local circumstances and wider socio‐economic trends and technical innovations. Furthermore, R&D performance, measured through outputs, impacts and income, has continually improved and increased.     

Non‐linear Predictability of UK Stock Market Returns*

Linear predictability of stock market returns has been widely reported. However, recently developed theoretical research has suggested that due to the interaction of noise and arbitrage traders, stock returns are inherently non‐linear, whereby market dynamics differ between small and large returns. This paper examines whether an exponential smooth transition threshold model, which is capable of capturing this non‐linear behaviour, can provide a better characterization of UK stock market returns than either a linear model or an alternate non‐linear model. The results of both in‐sample and out‐of‐sample specification tests support the exponential smooth transition threshold model and hence the belief that investor behaviour does differ between large and small returns.     

Alternative Forms of Mixing Banking with Commerce: Evidence from American History

Much of the discussion about banking and commerce in America has failed to make several crucial distinctions and has not accounted for many arrangements that have promoted the mixing of these activities. We investigate the history of banking and commerce in the United States, looking both at bank control of commercial firms and commercial firms' control of banks. We trace how these controls have changed with shifting definitions of "bank" and changing methods of "control." Despite the regulations prohibiting some arrangements that promote financial control, we find evidence of extensive linkages between banking and commerce in the United States. These linkages usually build on devices that are very close substitutes to the arrangements prohibited by law. Altogether, our findings question the often made claim that traditionally banking in the United States has been separated from commerce. Furthermore, given that research on Japan and Germany has shown that the mixing of banking and commerce matters for a variety of issues, our evidence also raises some questions on similar research in the United States which makes the simplifying assumption that these industries are separated.     

浅议“人才退出”机制

在经济全球化的今天,市场经济理念深入人心,人们逐渐接受了竞争意识、企业裁员已成为常有的事,但裁员的负面效应往往为人们所忽略,建立完善的人才退出机制任重而道远。     

Expenditure on different categories of meat in Greece: the influence of changing tastes

This paper employs a latent variable approach to isolate the effects of changing tastes on the share of total meat expenditure on different categories of meat products in Greece during the period 1965–1995. We find that changes in the relative expenditure on different categories of meat cannot be explained by changes in the relative prices of the different meat products and increased expenditure alone. For pork products in particular, the increase in the share of expenditure has been greater than would be expected as a result of the relative fall in their price. The increase can therefore be associated with changes in taste. This finding is of general interest to those conducting empirical research into consumer behaviour both in economies where there have been significant changes in patterns of food consumption, and where, as in the case of many less industrialised economies, rapid structural changes in food consumption patterns are still to come. It is also of importance to policy makers in assessing die effectiveness of advertising or promotional campaigns in influencing longer term changes in consumer preferences for different products.