Modeling the length and shape of the R&D lag: an application to UK agricultural productivity |
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| Authors: | Colin Thirtle Jenifer Piesse David Schimmelpfennig |
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| Institution: | Centre for Environmental Policy, Imperial College London, Exhibition Road, London SW7 2AZ, United Kingdom, and Department of Agricultural Economics, Extension and Rural Development, University of Pretoria, South Africa, Pretoria, South Africa;Department of Management, King's College London, 150 Stamford Street, London SE1 9HN, United Kingdom, and University of Stellenbosch, Republic of South Africa, Stellenbosch, South Africa;Economic Research Service, U.S. Department of Agriculture, 1800 M Street NW, Washington DC 20036-5831, USA |
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| Abstract: | This article updates total factor productivity (TFP) growth in UK agriculture from 1953–2005 and shows that public and private research and returns to scale explain TFP. Cointegration and causality tests are used to investigate the validity of attempts to explain UK agricultural productivity with R&D and related technology variables. Then, the length and shape of the lag structures are modeled and compared with the structures that are commonly imposed on the data. The rates of return (ROR) to R&D using the data determined lags differ considerably from those obtained by imposing lag shapes. These comparisons show that the ROR to public R&D are sensitive to the lag shape as well as its length and that the omission of other technology variables, such as mechanical and chemical patents pertaining to agriculture and farm size can bias the ROR. |
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| Keywords: | O33 Q16 |
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