|This dissertation explores three topics on agriculture and development using different applied econometric techniques. In the first chapter, Non-linear regression models were used to estimate the effect of own and other taxa previous population levels, nitrogen application, and crop rotation on population dynamics of plant parasitic and non-parasitic nematodes using data from the Cullars rotation. Because field experimental data was used, a spatial component was included as populations in one plot were proved to be related to the population level of their neighbors. Own previous levels were found to be very important for all groups of nematodes and all of the groups had an interaction effect with at least one other group. Lesion and cotton root-knot nematodes were found to be competitive while Mononchidae, Dorylaimidae, microbivorous and lance nematodes were non-competitive. All of the populations showed high seasonality patterns having lower populations during winter, to then remain steady until September-October when there is a significant increase in the population of cotton root-knot, Dorylaimidae, microbivorous, and lesion nematodes. Nitrogen had a positive effect on Mononchidae, microbivorous, spiral, and cotton root-knot nematodes. The use of clover after cotton in the rotation crop program proved to be significantly better in reducing plant parasitic nematodes compared to other treatments.
The second chapter analyzed the market structure of Peruvian agricultural exports as Peru has become the largest fresh asparagus exporter, third in processed artichoke, and third in paprika. This may have generated market power but the exertion of it and towards whom has not ii
been studied yet. Pricing-To-Market (PTM) models tested for price discrimination in the Peruvian export market for these three goods. The results strongly suggested that Peruvian exporters were engaging in price discriminating behavior. Country markups were common and Peruvian exporters were stabilizing English pound prices in asparagus and Euro prices in paprika. Lastly, even though PTM found that fresh asparagus exporters were amplifying the effects of the exchange rate after the preferential free trade agreement between U.S. and Peru was established, the crucial assumption of constant marginal cost in the framework may be too restrictive to affirm that an incomplete exchange rate pass-through is happening.
The third chapter addressed a development topic related to the labor market in the U.S. In the U.S., Hispanic people carry a greater stigma regarding their immigration status compared to other ethnicities. This study focused on citizenship status’ effect on wages using quantile wage regressions accounting for sample selection in the states of Alabama and Georgia. Wages for two groups were analyzed: Hispanics and non-Hispanics (all other ethnicities). Results suggested that using an average estimation of the effect of citizenship on wages for non-Hispanics does not reflect what is really happening in the different quantiles. For the Hispanic group, all the quantiles showed a significant positive coefficient (of having citizenship) and a higher magnitude in the lower one. However, this higher magnitude was not economically significant compared to the other quantiles. It is concluded that Hispanic are negatively affected by not having the proper immigration status regardless of the quantile they are in, thus an average effect regression provides a good fit for testing the impact of citizenship status on Hispanic people.