


Registros recuperados: 15  


Hertzler, Greg. 
Stochastic differential equations are a flexible way to model continuous probability distributions. The most popular differential equations are for nonstationary Lognormal, nonstationary Normal and stationary OrnsteinUhlenbeck distributions. The probability densities are known for these distributions and the assumptions behind the differential equations are well understood. Unfortunately, the assumptions do not fit most situations. In economics and finance, prices and quantities are usually stationary and positive. The Lognormal and Normal distributions are nonstationary and the Normal and OrnsteinUhlenbeck distributions allow negative prices and quantities. This study derives a stochastic differential equation that includes most of the classical... 
Tipo: Conference Paper or Presentation 
Palavraschave: Research Methods/ Statistical Methods. 
Ano: 2003 
URL: http://purl.umn.edu/57891 
 


Gorddard, Russell J.; Pannell, David J.; Hertzler, Greg. 
The presence of weeds which have developed resistance to chemical herbicides is a problem of rapidly growing importance in Australian agriculture. We present an optimal control model of herbicide resistance development in ryegrass, the weed for which resistance is most commonly reported. The model is used to select the optimal combination of chemical and nonchemical control measures taking account of the trade off between short term profits and the long term level of herbicide resistance. Results indicate that given the threat of resistance there are benefits from integrating a combination of chemical and nonchemical control measures. The optimal strategy is found to include a declining herbicide dosage as resistance develops, with compensatory increases... 
Tipo: Journal Article 
Palavraschave: Research and Development/Tech Change/Emerging Technologies. 
Ano: 1995 
URL: http://purl.umn.edu/22858 
 


Hertzler, Greg. 
Following the dismantling of a pricesupport program, a central bureaucracy is left with a commodity stockpile to dispose. It happened with wheat and feed grains in the U.S. in 1986 and wool in Australia in 1991. It soon may happen in Europe with grains, manufactured dairy products and other commodities which have supported prices. Obvious policies include privatising the stockpile, disposing of the stockpile by a central bureaucracy and quarantining the stockpile from the market. Each policy imposes constraints on disposal based, perhaps, on judgments of political acceptability to producers and government. In this article, optimal rules for production and disposal are derived and solved and a new policy is proposed. Then the model is applied to the... 
Tipo: Journal Article 
Palavraschave: Demand and Price Analysis; Productivity Analysis. 
Ano: 1994 
URL: http://purl.umn.edu/22427 
 


Tregeagle, Daniel; Harris, Michael; Hertzler, Greg. 
Economic research on the consumption of harmful goods focuses principally on the addictive nature of consumption rather than its impacts on health, despite medical research showing that consumers primarily consider health effects when making decisions about addictive behaviour. In this paper, the standard rational addiction model is recast in terms of a resource depletion problem, where the resource in question is a depletable stock of health, and the time horizon is finite. Analysis of the prototype health depletion model finds two types of consumption path, one that is compatible with the results from rational addiction and one that is not. Several extensions to the prototype model are explored. 
Tipo: Conference Paper or Presentation 
Palavraschave: Resource /Energy Economics and Policy. 
Ano: 2011 
URL: http://purl.umn.edu/100723 
 

 


Hertzler, Greg. 
Cattle purchasing, feeding, and selling decisions are described by a freetime optimal control model. The nutrient constraints of the National Research Council and a recently published dry matter intake constraint augment the model and make it nonlinear in the feed ingredients, the daily gain, and the weight of the cattle. Optimal feeding programs are calculated by nonlinear programming under two scenarios: first, when the feedlot has excess capacity and, second, when animals must be sold to make room in the feedlot before more can be purchased. An approximately optimal feeding program is calculated by nonlinear programming and is all but identical to the dynamically optimal programs. 
Tipo: Journal Article 
Palavraschave: Livestock Production/Industries. 
Ano: 1988 
URL: http://purl.umn.edu/32165 
 


MacAulay, T. Gordon; Hertzler, Greg. 
A problem encountered in the econometric estimation of dynamic models of livestock systems is dynamic instability during simulation of models. In the case of systems where economic decisions are involved in the breeding and the slaughter of animals it is possible for parameters to be obtained which generate dynamic instability. In the paper, a simple representation of the dynamics of a livestock system is examined using techniques of dynamic analysis. The dynamic stability of such models depends fundamentally on the parameters determining the births and deaths and thus the relative flows in and out of the stock of animals. In some situations very narrow stability ranges for the values of the parameters are observed. 
Tipo: Presentation 
Palavraschave: Dynamic models; Beef herd; Dynamic instability; Dynamic processes; Livestock Production/Industries. 
Ano: 2000 
URL: http://purl.umn.edu/123699 
 

 


MacAulay, T. Gordon; Hertzler, Greg. 
In this paper a model is developed which brings together elements of the household models, spatial trading systems and demand systems with elements of production and income risk. Some of the implications of the design are analysed. The design is focussed on the problem faced by Vietnamese farm households as they face land use policy changes which will allow for the possibility of land consolidation, reduced input subsidies and increased market risk. 
Tipo: Presentation 
Palavraschave: Consumer/Household Economics; Farm Management. 
Ano: 2000 
URL: http://purl.umn.edu/123701 
 


Doole, Graeme J.; Hertzler, Greg. 
The capacity of global agricultural production to meet increased demand for food from population growth and wealth accumulation is threatened by extensive land degradation. Nonetheless, previous research has focused primarily on the dynamic implications of input management and ignored landuse choice. This paper extends this theory through an examination of the intertemporal management of agricultural land through the use of noncrop inputs, such as fertilizer, and land uses that either degrade or restore productivity. The need to consider the relative total asset value of alternative crops over time is demonstrated. Moreover, higher output prices for degrading crops are shown to increase their relative value, motivating the later adoption of substitutes.... 
Tipo: Journal Article 
Palavraschave: Crop sequences; Land degradation; Regime switching; International Development; Production Economics; Q15; Q24. 
Ano: 2011 
URL: http://purl.umn.edu/100643 
 

 

 


Zhang, Jing; Hertzler, Greg; Burton, Michael P.. 
Australia by using the data from the newly finished National Survey of Recreational Fishing (2000/2001)(NSRF). There are a number of findings. 1. Socioeconomic characteristics of anglers didn’t affect their catch of high quality fish (prize fish, reef fish or keysport fish) as much as their catch of low quality fish (table fish and butter fish). 2. For a given trip, anglers were willing to pay $1.63, $26.03, $1.03 and $0.53 for the first prize fish, reef fish, keysport fish or butter fish caught, respectively. 3. The top four valuable fishing sites in the survey period were Geraldton, Esperance, Albany and Broome, with annual access values of $6.45 million, $4.52 million, $3.47 million and $2.47 million, respectively. 4. The per trip estimates are of... 
Tipo: Conference Paper or Presentation 
Palavraschave: Recreational fishing; Random utility model; Nonmarket valuation; Production Economics; Research Methods/ Statistical Methods. 
Ano: 2003 
URL: http://purl.umn.edu/58275 
 


Hertzler, Greg. 
This paper develops methods to quantify weather derivatives and yield index insurance. These are exotic options that differ from financial options in several ways. The underlying random variable is not a price but a quantity such as millimeters of rainfall. Instead of option "pricing", a method must be developed for option "quantifying". Financial options are tradable. Weather derivatives and yield index insurance are not. Instead of being priced continuously, these are quantified once when the contract is written. As a result, they are less flexible. Financial options are linear. The probability distribution of an option is easily found from the probability distribution of the underlying price. Yield index insurance is a contract written on a nonlinear... 
Tipo: Conference Paper or Presentation 
Palavraschave: Financial Economics. 
Ano: 2004 
URL: http://purl.umn.edu/58705 
 
Registros recuperados: 15  


