Spatial externalities: Evidence on social interaction, market expansion and mineral extraction from Brazil and India.

摘要

Various externalities embedded in human-environment interactions need to be accounted to assess the sustainability of environment and development policies. In this dissertation, I examine three such externalities related to - (i) information spillover regarding agricultural technology through social networks; (ii) integration of milk markets on pasture management choices; (iii) public health impacts of iron ore extraction. The land use and health outcomes I examine are of considerable current policy relevance, as (i) and (ii) are inextricably linked with deforestation in the Brazilian Amazon, while (iii) deals with public health impacts of iron ore mining in India.;The analyses is based on a combination of geo-referenced longitudinal household survey data, GIS data on market and road infrastructure, and classified land cover information from satellite images. The spatial information helps operationalize and quantify the externalities examined in each essay - (i) specification of the reference group (both spatial neighbors and members in the social network) that could influence land use decisions of individual farmers; (ii) constructing distance-based measures between location of farmers and all milk plants, based on the assumption that diminishing distances between them over time indicates expansion of the milk market; (iii) distancebased metrics of proximity of households to iron ore mining areas as a proxy for exposure to environmental pollution from mines.;The policy to support extension and dissemination of technology, credit and marketing through agricultural cooperatives is justified on the grounds that collective learning creates a multiplier effect that amplifies the adoption of desirable land use strategies. I find evidence in favor of endogenous social interaction effect, as land use decisions of other members in the social network based on common membership in agricultural cooperatives in the Brazilian Amazon are found to influence choices of individual farmers.;If increased profit from cattle ranching is utilized in intensification of pastures rather than extensification, then policies to support the growth of dairy and beef markets could reduce the propensity of small farmers to deforest and migrate in the Amazon frontier. Though I find weak evidence in favor that expanded market opportunities encourage farmers to intensify, it has mostly followed extensive deforestation. While mines create short term employment benefits and long term development in public infrastructure, they also create negative externalities through pollution and environmental degradation. I find that the environmental health impacts of mines increase the incidence and workdays lost due to Acute Respiratory Illness, while the latter is true for Malaria.