27,759 research outputs found
Modelling the Effect of Policy Reform on Structural Change in Irish Farming
End of project reportThe Mid Term Review (MTR) of the Common Agricultural Policy (CAP) has allowed for the decoupling of all direct payments from production from 2005 onwards; until then, most direct payments were coupled to production, requiring farmers to produce specific products in order to claim support. After decoupling, farmers will receive a payment regardless of production as long as their farm land is maintained in accordance with good agricultural practices. Direct payments to farmers have been an integral part of the CAP since the 1992 Mac Sharry reforms. Throughout the 1990s, market prices for farm produce have declined generally in line with policy while costs of production have continued to increase. Meanwhile, direct payments increased in value, increasing farmers’ reliance on this source of income. Furthermore, farmers adapted farming practices to maximise their receipt of direct payments, leading to the culture of ‘farming the subsidy’. By 1997, on cattle and tillage farms in Ireland 100 per cent of family farm income was derived from direct payments, meaning that on average the market-based revenue was insufficient to cover total costs
GENEDEC
End of Project reportGENEDEC was a European project funded under the 6th Framework. It was co-ordinated by INRA Grignon with ten European partners and a time frame of 42 months. The purpose of the project was to conduct a quantitative and qualitative assessment of the socio-economic and environmental impacts of the decoupling of direct payments on agricultural production, markets and land use in the EU. It was envisaged that the pan-EU nature of the project would facilitate an international comparison of the effects of decoupling and would provide policy makers with sufficient information to identify the key winners and losers from decoupling throughout the EU. The project aimed to provide insights into the workability of decoupling and its impacts, and to analyse alternative policy options to improve the agricultural support system. Specifically, through the use of farm level models, this project estimated the effects of existing and proposed decoupled support schemes on production, land use and land prices and the implications for farm incomes and the future structural development of farms. The project was divided into 9 Work Packages depending on objectives and time frame of the project. The main role of RERC Teagasc was in Work Package 2 which aimed to develop farm level mathematical models and used the models developed to determine the impact of decoupling on Irish farms. The work in RERC started in November 2004 and ended in May 2006. A brief description of the models developed and results generated by RERC is provided here.GENEDEC was a European project funded under the 6th Framework
Modelling Probabilistic Wireless Networks
We propose a process calculus to model high level wireless systems, where the
topology of a network is described by a digraph. The calculus enjoys features
which are proper of wireless networks, namely broadcast communication and
probabilistic behaviour. We first focus on the problem of composing wireless
networks, then we present a compositional theory based on a probabilistic
generalisation of the well known may-testing and must-testing pre- orders.
Also, we define an extensional semantics for our calculus, which will be used
to define both simulation and deadlock simulation preorders for wireless
networks. We prove that our simulation preorder is sound with respect to the
may-testing preorder; similarly, the deadlock simulation pre- order is sound
with respect to the must-testing preorder, for a large class of networks. We
also provide a counterexample showing that completeness of the simulation
preorder, with respect to the may testing one, does not hold. We conclude the
paper with an application of our theory to probabilistic routing protocols
Using higher-order contracts to model session types
Session types are used to describe and structure interactions between
independent processes in distributed systems. Higher-order types are needed in
order to properly structure delegation of responsibility between processes.
In this paper we show that higher-order web-service contracts can be used to
provide a fully-abstract model of recursive higher-order session types. The
model is set-theoretic, in the sense that the meaning of a contract is given in
terms of the set of contracts with which it complies.
The proof of full-abstraction depends on a novel notion of the complement of
a contract. This in turn gives rise to an alternative to the type duality
commonly used in systems for type-checking session types. We believe that the
notion of complement captures more faithfully the behavioural intuition
underlying type duality.Comment: Added definitions of m-closed terms, of 'dual', and a discussion to
show the problems of the complement functio
Feeding and the Equilibrium Feeder Animal Price-Weight Schedule
Feeder animal prices depend on fed animal prices, the biological growth technology, and feed costs. In addition, daily maintenance costs can be avoided through accelerated feeding. These observations allow us to model optimal feeding under equilibrium feeder animal pricing. Our model enables a better understanding of regulation in feedstuff markets. The feeder animal price-weight schedule is likely decreasing and convex in weight. Prices for animals with better growth potential should be less sensitive to feed and fed animal prices. Prices for lighter animals should be more sensitive to these prices. Regression analyses on Southern Great Plains cattle prices provide support for this model.days on feed, energy use, feed ban, growth hormones, Kleiber's law, ration density, veal market, Livestock Production/Industries,
Modeling Stochastic Crop Yield Expectations with a Limiting Beta Distribution
The use of plausible stochastic price processes in price risk analysis has allowed advances not seen in crop yield risk analysis. This study develops a stochastic process for yield modeling and risk management. The Pólya urn process is an internally consistent dynamic representation of yield expectations over a growing season that accommodates agronomic events such as growing degree days. The limiting distribution is the commonly used beta distribution. Binomial tree analysis of the process allows us to explore hedging decisions and crop valuation. The method is empirically flexible to accommodate alternative assumptions on the growing environment, such as intra-season input decisions.crop abandonment, crop insurance, derivative analysis, growing degree days, Pólya’s urn, stochastic process, Crop Production/Industries,
Seasonality and Costs of Production on Irish dairy farms from 1994-2008
working paperPrevious research has highlighted the economic advantages of spring calving in
countries such as Ireland that have a long spring/summer grazing season. However,
the widespread adoption of such a production system leads to a highly seasonal milk
supply and a range of problems that are associated with seasonality. The objective of
this paper is to use historical data to quantify the economic benefits of a spring
calving system. Data from over 400 dairy farms in Ireland over a period of 15 years is
examined. Fixed, random and between effects panel models are estimated to test the
significance of calving season on production costs. The results show the effect of
calving season is significant at lowering production costs. These models returned
results suggesting that high compact early Spring herds have significantly lower costs
than over seasons. However the fixed effect model demonstrates little difference
between production costs in different seasons suggesting individual effects such as the
ability of the farmer may play a role in reduction of costs. Herds that are calved over a
shorter period tend to have lower production costs
The role of non-pecuniary benefits in the labour allocation decision of farmers.
working paperPrevious research has primarily focused on the impact of economic variables in
explaining the off farm labour allocation decisions of principal farm operators. This study
finds attitudes regarding the non-pecuniary benefits associated with the farming lifestyle
also significantly affect behaviour by acting as a strong disincentive to farmers towards
working off farm. This may suggest that even if economic returns are greater in the offfarm
labour market, farmers may not supply additional labour off farm. We also
employed separate models of off-farm labour market participation and off-farm labour
supply and found certain variables such as a farm operator’s age and the level of
diversification undergone by the farm business affect off farm labour market participation
and hours supplied differently
THE DESEASONALIZATION OF ANIMAL PRODUCTION
We document the deseasonalization of animal production in the US and Europe. Hypotheses on causes and consequences of this trend are advanced. They pertain to feed costs, changes in animal productivity and cost fixity of the underlying technology, innovations in genetic control and epidemiology, and the capital intensity of production.Animal Production, Capital Intensity, Dairy, Industrialization, Seasonality, Livestock Production/Industries,
Economic Value of Information: Wheat Protein Measurement
In this paper we study U.S. wheat farmers’ willingness to pay for near infrared (NIR) sensor that can segregates wheat grains according to their protein concentration. We first develop a microeconomic optimization model of wheat farmers’ segregating and commingling decisions. Then we use U.S. wheat prices and stocks to estimate a wheat protein stock demand system. This allows us to establish the effects of changes in the protein profile of wheat stocks on protein premiums. The paper’s simulation section combines the results from the microeconomic optimization model and from the econometric estimations to simulate wheat farmers’ WTP for the sorting technology. Preliminary findings from the simulation show that a typical hard red winter (hard red spring) wheat farmer’s WTP for the sorting technology is 5.6 (4.8) cents per bushel.information, economic value, wheat, protein, market structure, Crop Production/Industries, Production Economics, Q12, Q16, D81,
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