SABIIA - Sistema Aberto e Integrado de Informação em Agricultura (Sabiia)

A discrete choice dynamic model was used to predict land use change for an area in Panama. Our results show not only that our modeling technique performs better than static models, but it is also superior to previous attempts to model land use change in a dynamic fashion.

AN ASSESSMENT OF WORKAROUNDS FOR SPATIAL EFFECTS IN THE CASE OF BINARY PROBIT

Palavras-chave: Land Economics/Use.

Ano: 2004

URL: http://purl.umn.edu/20314

Robertson, Richard D.; Nelson, Gerald C..

The consequences of spatial effects on discrete choice models have not been well established. Various ad hoc workarounds have been proposed to mitigate potential estimation problems. This paper employs Monte Carlo simulation to investigate the severity of the problems introduced by spatial effects and the effectiveness of the workarounds.

Assessing the Robustness of Predictions in Spatially Explicit Models of Land Use

Palavras-chave: Research Methods/ Statistical Methods.

Ano: 2004

URL: http://purl.umn.edu/20234

We propose an information-theoretic approach to assess the performance of a discrete choice model used to analyze land use and land use change. We show that our disaggregated measure can be used to compare robustness of predictions across land use categories and across models. Furthermore, a proper reformulation of the problem shows that a disaggregated (observation by observation) log-likelihood lends itself to an information theoretic interpretation, which allows comparisons performance across models.

CORRECTING FOR SPATIAL EFFECTS IN LIMITED DEPENDENT VARIABLE REGRESSION: ASSESSING THE VALUE OF "AD-HOC" TECHNIQUES

Palavras-chave: Land Economics/Use.

Ano: 2006

URL: http://purl.umn.edu/21307

A common test for spatial dependence in regression analysis with continuous dependent variables is the Moran's I. For limited dependent variable models, the standard definition of a residual breaks down because yi is qualitative. Efforts to correct for potential spatial effects in limited dependent variable models have relied on ad-hoc methods such as including a spatial lag variable or using a regular sample that omits neighboring observations. Kelejian and Prucha have recently developed a version of Moran's I for limited dependent variable models. We present the statistic in a more accessible way and use it to test the value of previously-used ad-hoc techniques with a specific data set. Keywords: Morans I, Spatial Autocorrelation, Limited Dependent...

IS A BEEF DEFICIENCY PAYMENT PARETO-SUPERIOR IN SOUTH KOREA?

Palavras-chave: Moran's I; Spatial Autocorrelation; Limited Dependent Variable Models; Land-Use Change; Geographical Information Systems (GIS); Research Methods/ Statistical Methods.

Ano: 2002

URL: http://purl.umn.edu/19782

Nelson, Gerald C.; Lee, Yong-Kee.

South Korea uses a quota and a tariff on beef imports to keep farm prices high. Part of the quota rents are used to support indirect benefits to producers. The welfare costs of these policies are analyzed. Following a suggestion of Hayami, a deficiency payment financed by tariff revenues from increased imports is considered as an alternative to the quota. As Anderson (1983) found for Japan, a deficiency payment is Pareto-superior only if indirect benefits from the quota revenue are ignored.

Tipo: Journal Article

Palavras-chave: International Relations/Trade.

Ano: 1991

URL: http://purl.umn.edu/32622

Modeling Deforestation and Land Use Change: Sparse Data Environments

Land use change in developing countries is of great interest to policymakers and researchers from many backgrounds. Concerns about consequences of deforestation for global climate change and biodiversity have received the most publicity, but loss of wetlands, declining land productivity, and watershed management are also problems facing developing countries. In developing countries, analysis is especially constrained by lack of data. This paper reviews modeling approaches for data-constrained environments that involve methods such as neural nets and dynamic programming and research results that link individual household survey data with satellite images using geographic positioning systems.

The Information Technology Revolution and Higher Education

Palavras-chave: Land Economics/Use; Q15; Q23; R14.

Ano: 2006

URL: http://purl.umn.edu/25723

What is the irrigation potential for Africa? A Combined Biophysical and Socioeconomic Approach

Nelson, Gerald C..

Higher education is under pressure from state legislatures and other clients to reduce costs. Two information technologies - increased computing power on the desktop and the World Wide Web - have shifted out the meta production function for instruction in higher education. The theory of induced innovation provides hypotheses about the kinds of educational practices that will attract technological change. Several sources of inefficiency in higher education are identified and likely technology-driven changes suggested. These innovations will provide the means to reduce costs in higher education.

Tipo: Journal Article

Palavras-chave: Induced innovation; Learning technologies; World Wide Web; Agribusiness; Teaching/Communication/Extension/Profession.

Ano: 1996

URL: http://purl.umn.edu/90399