In Situ Conservation Of Crop Genetic Resources In The Mexican Milpa System
This dissertation focuses on the theoretical modeling and empirical testing of household motivations for the in situ conservation of crop genetic resources (CGR). An original household survey is used to test whether the household diversity outcomes are different for the cropping system as a whole, for the principal crop, maize, or for the secondary crops, beans and squash. Agro-ecological characteristics and market characteristics are found to significantly affect the levels of diversity maintained by households. A review of the economic literature relevant to modeling in situ conservation is presented. A theoretical model is developed in which a household's decision to plant a milpa variety is linked to household, agro-ecological, and market variables. A household farm model appropriate to CGR conservation is presented, and extended to the case of missing markets. The agricultural ecology of the Sierra Norte de Puebla is described, as well as the principal CGR in the milpa system. The empirical methodology uses a Poisson regression, for the total number of crop varieties and for each crop group separately. The econometric work is extended to a hurdle model for sample selection, and a SUR model utilizing a Shannon diversity index as a linear measure of diversity. The results from the regressions of household level diversity show that a range of household, village, environmental, and market conditions affect the diversity outcomes. Market integration, measured by distance to a regional market, use of hired labor, and international migration, were found to negatively affect diversity outcomes. Agro-ecological conditions, measured by the number of plots, plots with different slopes, and the high altitude region, all were found to positively increase household diversity outcomes. The econometric findings were different for the combined milpa system than individual crops, and individual crops were affected by different factors. The principal crop, maize, seems mainly affected by the agro-ecological characteristics, while the levels of market integration are found to affect the minor crops, beans and squash. Conclusions are presented on the links between this study and conservation planning issues, and possible directions for future research are discussed.
|Date of creation:||2000|
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- J. Edward Taylor & Scott Rozelle & Alan deBrauw, 1999. "Migration, Remittances, and Agricultural Productivity in China," American Economic Review, American Economic Association, vol. 89(2), pages 287-291, May.
- Hellerstein, Daniel & Mendelsohn, Robert, 1993.
"A Theoretical Foundation for Count Data Models,"
25265, University Library of Munich, Germany.
- Lee, Lung-Fei, 1978. "Unionism and Wage Rates: A Simultaneous Equations Model with Qualitative and Limited Dependent Variables," International Economic Review, Department of Economics, University of Pennsylvania and Osaka University Institute of Social and Economic Research Association, vol. 19(2), pages 415-33, June.
- Martin L. Weitzman, 1992.
The Quarterly Journal of Economics,
Oxford University Press, vol. 107(2), pages 363-405.
- Weitzman, M.L., 1991. "On Diversity," Harvard Institute of Economic Research Working Papers 1553, Harvard - Institute of Economic Research.
- Simpson, R David & Sedjo, Roger A & Reid, John W, 1996. "Valuing Biodiversity for Use in Pharmaceutical Research," Journal of Political Economy, University of Chicago Press, vol. 104(1), pages 163-85, February.
- Cameron, A. Colin & Trivedi, Pravin K., 1990. "Regression-based tests for overdispersion in the Poisson model," Journal of Econometrics, Elsevier, vol. 46(3), pages 347-364, December.
- Brush, Stephen B. & Taylor, J. Edward & Bellon, Mauricio R., 1992. "Technology adoption and biological diversity in Andean potato agriculture," Journal of Development Economics, Elsevier, vol. 39(2), pages 365-387, October.
- Derek Byerlee & Edward Souza, 1997. "Wheat Rusts and the Costs of Genetic Diversity in the Punjab of Pakistan," American Journal of Agricultural Economics, Agricultural and Applied Economics Association, vol. 79(3), pages 726-737.
- Derek Byerlee & Edith Hesse de Polanco, 1986. "Farmers' Stepwise Adoption of Technological Packages: Evidence from the Mexican Altiplano," American Journal of Agricultural Economics, Agricultural and Applied Economics Association, vol. 68(3), pages 519-527.
- Just, Richard E., 2000. "Some Guiding Principles For Empirical Production Research In Agriculture," Agricultural and Resource Economics Review, Northeastern Agricultural and Resource Economics Association, vol. 29(2), October.
- Heckman, James J, 1979.
"Sample Selection Bias as a Specification Error,"
Econometric Society, vol. 47(1), pages 153-61, January.
- Mullahy, John, 1986. "Specification and testing of some modified count data models," Journal of Econometrics, Elsevier, vol. 33(3), pages 341-365, December.
- Bellon, Mauricio R & Taylor, J Edward, 1993. ""Folk" Soil Taxonomy and the Partial Adoption of New Seed Varieties," Economic Development and Cultural Change, University of Chicago Press, vol. 41(4), pages 763-86, July.
- Melinda Smale & Richard E. Just & Howard D. Leathers, 1994. "Land Allocation in HYV Adoption Models: An Investigation of Alternative Explanations," American Journal of Agricultural Economics, Agricultural and Applied Economics Association, vol. 76(3), pages 535-546.
- Gomez, Jose Alfonso Aguirre & Bellon, Mauricio R. & Smale, Melinda, 1998. "A Regional Analysis of Maize Biological Diversity in Southeastern Guanajuato, Mexico," Economics Working Papers 7671, CIMMYT: International Maize and Wheat Improvement Center.
- Widawsky, David & Rozelle, Scott & Jin, Songqing & Huang, Jikun, 1998.
"Pesticide productivity, host-plant resistance and productivity in China,"
Agricultural Economics of Agricultural Economists,
International Association of Agricultural Economists, vol. 19(1-2), September.
- Widawsky, David & Rozelle, Scott & Jin, Songqing & Huang, Jikun, 1998. "Pesticide productivity, host-plant resistance and productivity in China," Agricultural Economics, Blackwell, vol. 19(1-2), pages 203-217, September.
- Winfried Pohlmeier & Volker Ulrich, 1995. "An Econometric Model of the Two-Part Decisionmaking Process in the Demand for Health Care," Journal of Human Resources, University of Wisconsin Press, vol. 30(2), pages 339-361.
- Smale, Melinda & Bellon, Mauricio R. & Gomez, Jose Alfonso Aguirre, 1999. "The Private and Public Characteristics of Maize Land Races and the Area Allocation Decisions of Farmers in a Center of Crop Diversity," Economics Working Papers 7669, CIMMYT: International Maize and Wheat Improvement Center.
- Feder, Gershon & Just, Richard E & Zilberman, David, 1985. "Adoption of Agricultural Innovations in Developing Countries: A Survey," Economic Development and Cultural Change, University of Chicago Press, vol. 33(2), pages 255-98, January.
- Howard D. Leathers & Melinda Smale, 1991. "A Bayesian Approach to Explaining Sequential Adoption of Components of a Technological Package," American Journal of Agricultural Economics, Agricultural and Applied Economics Association, vol. 73(3), pages 734-742.
- Solow Andrew & Polasky Stephen & Broadus James, 1993. "On the Measurement of Biological Diversity," Journal of Environmental Economics and Management, Elsevier, vol. 24(1), pages 60-68, January.
- Gershon Feder, 1982. "Adoption of Interrelated Agricultural Innovations: Complementarity and the Impacts of Risk, Scale, and Credit," American Journal of Agricultural Economics, Agricultural and Applied Economics Association, vol. 64(1), pages 94-101.
- George A. Akerlof, 1970. "The Market for "Lemons": Quality Uncertainty and the Market Mechanism," The Quarterly Journal of Economics, Oxford University Press, vol. 84(3), pages 488-500.
- Benjamin, Dwayne, 1992. "Household Composition, Labor Markets, and Labor Demand: Testing for Separation in Agricultural Household Models," Econometrica, Econometric Society, vol. 60(2), pages 287-322, March.
- Just, Richard E & Zilberman, David, 1983. "Stochastic Structure, Farm Size and Technology Adoption in Developing Agriculture," Oxford Economic Papers, Oxford University Press, vol. 35(2), pages 307-28, July.
- Pitt, Mark M & Sumodiningrat, Gunawan, 1991. "Risk, Schooling and the Choice of Seed Technology in Developing Countries: A Meta-Profit Function Approach," International Economic Review, Department of Economics, University of Pennsylvania and Osaka University Institute of Social and Economic Research Association, vol. 32(2), pages 457-73, May.
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