This article focuses on agricultural productivity growth at both sector and state levels. It does so in a way that preserves the economic integrity of national and state production accounts. A model accounting for interstate transactions in farm goods links sectorwide and state-specific measures of total factor productivity growth. An interesting conclusion is that the smooth, persistently positive trend typically observed for farm sector productivity growth masks considerable variation across states and regions. The results also indicate that farm sector productivity growth is wholly a function of productivity trends in the individual states. Interstate shifts in production activity and resource reallocations have had little impact. Copyright 1999, Oxford University Press.
This paper studies the impact of wind generation on system balancing costs. The paper makes use of a novel and rich dataset on half-hourly and five-minute generation by fuel and generation type and system balancing prices and volumes made available by the UK market and systems operator for every period from November 2008 to November 2011. An econometric cost function approach is used, where the total cost of balancing is regressed against wind generation and other explanatory variables. A number of specifications are tested and the regression diagnostics indicate an important correction for serial correlation. The results indicate that there are statistically significant impacts on system balancing costs from wind; more wind generation increases system balancing costs. However, the best-fit equation is quadratic in wind generation, and so the cost impact of wind generation on balancing costs is increasing at a decreasing rate; the marginal cost is positive but decreasing and linear. At high levels of wind generation and given the existing generation portfolio the balancing cost impact is statistically zero. Moreover, under a range of specifications, the magnitude of these costs is not high relative to total system balancing costs and the cost of power in the UK. We conclude that balancing system impacts of wind for five to ten GW of installed capacity in the UK are not likely to be high, given the estimated current average cost of about €0.01 over all the power transported on the GB system.
Abstract--This paper studies the impact of wind generation on system costs and prices in Ireland. The need to mitigate climate change, achieve renewables energy targets, and use renewable sources of energy means that many countries are considering greater levels of wind generation in their power generation mix. The overall impact of wind generation on system costs and performance has only been studied recently, and often with limited actual data from power systems with increased wind penetration. The paper uses a unique dataset of half-hourly system demand, generation, wind forecast generation, and actual wind generation, along with Irish system marginal price (SMP) data from 2008 to autumn 2012. An econometric time-series model of SMP as a function of forecast and realized demand and wind generation is formed. The costs of balancing and system constraints are included in the cost of 'uplift', and thus the total cost of a variety of factors is included in our estimates for Ireland. Our results suggest that each 1% increase in wind generation reduces SMP in Ireland by about 0.06%, while each 1% wind forecast error increases SMP about 0.02%. In absolute terms, though, at the mean the impact of wind forecast errors is small, or about 0.4€cent/MWh-wind generated. However, the impact per MWh forecast error is about €1.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.