This study used the by-production model specification to separate emission-generating technologie... more This study used the by-production model specification to separate emission-generating technologies from 'desirable outputs' technology. It then employed the dynamic efficiency model, following the Dynamic Directional Input Distance Function specifications to compute the deterministic, dynamic environmental and technical efficiencies of large gold mines in developing countries. Using firm-level data from 2009 to 2018, the study found that on average, dynamic technical efficiency in these mines was 73%; the average dynamic technical efficiency was observed to have a decreasing trend, of 0.3% annually. The study also found that on average, dynamic environmental efficiency was 56%. However, the average dynamic environmental efficiency trend had a decrease of 0.6% annually. The poor performance and downward trends could be attributed partly to downward investment trends over time, and the increasing complexity of extracting gold deposits from low-grade ore, as well as to prices. They could also be the result either of poor institutional capacity, as far as environmental policies, regulations, and enforcement are concerned; or of supply-side structural rigidity-in particular, low-capacity, and unreliable energy supply, mostly from bad inputs such as coal and heavy fuels or both, which calls for the use of alternative energy sources.
This article examines an important externality that polluting industries may impose on peoples’ h... more This article examines an important externality that polluting industries may impose on peoples’ health in their proximities. To ascertain the actual health outcomes and expenditure associated with mining pollution, this study (on a gold mine in Tanzania) used the Coarsened Exact Matching (CEM) approach, which matches the social, economic, and environmental risk-factor characteristics of households in treated and control groups. It also used a linear and logistics regression using CEM Weight to obtain robust treatment effects. The results show that health outcomes (proxied by stunting rate) were significant within 10km of the nearby mine. The probability of a child in the treated group being stunted was 0.226 greater than for a child with similar social, economic and environmental risk factors in the control group. Moreover, the OLS regression suggested similarly that the children in the treated group had height-for-age Z-scores (HAZ06) of 0.827 less than for similar children in the ...
This study evaluates the environmental performance of large gold-mining operations by applying a ... more This study evaluates the environmental performance of large gold-mining operations by applying a by-production model that specifies emission-generating technology, while incorporating a four-way error approach that captures mine-size heterogeneity, transient and persistent technical efficiency, and random errors. We applied a true random effects model (TREM), and a simulated maximum likelihood estimator (SMLE) based on the generalised true random effects model (GTREM). Firm-level data from 2009 to 2018 were used; the results show the presence of environmental and technical inefficiencies. Moreover, each inefficiency was decomposed into transient and persistent inefficiencies. The overall environmental performance of the mines in developing countries is low (66%) compared to other sectors, which indicates that there could be structural rigidities, poor environmental policies and regulations, poor enforcement, or any combination of the three. We also found robust empirical evidence that between 2009 and 2018, on average, gold-mining firms neither strongly increased nor strongly decreased their transient or their persistent technical and environmental efficiency. Besides, firms with high technical efficiency simultaneously have high environmental efficiency, which suggests that promoting high environmental efficiency will also promote high technical efficiency.
This study used the by-production model specification to separate emission-generating technologie... more This study used the by-production model specification to separate emission-generating technologies from 'desirable outputs' technology. It then employed the dynamic efficiency model, following the Dynamic Directional Input Distance Function specifications to compute the deterministic, dynamic environmental and technical efficiencies of large gold mines in developing countries. Using firm-level data from 2009 to 2018, the study found that on average, dynamic technical efficiency in these mines was 73%; the average dynamic technical efficiency was observed to have a decreasing trend, of 0.3% annually. The study also found that on average, dynamic environmental efficiency was 56%. However, the average dynamic environmental efficiency trend had a decrease of 0.6% annually. The poor performance and downward trends could be attributed partly to downward investment trends over time, and the increasing complexity of extracting gold deposits from low-grade ore, as well as to prices. They could also be the result either of poor institutional capacity, as far as environmental policies, regulations, and enforcement are concerned; or of supply-side structural rigidity-in particular, low-capacity, and unreliable energy supply, mostly from bad inputs such as coal and heavy fuels or both, which calls for the use of alternative energy sources.
This article examines an important externality that polluting industries may impose on peoples’ h... more This article examines an important externality that polluting industries may impose on peoples’ health in their proximities. To ascertain the actual health outcomes and expenditure associated with mining pollution, this study (on a gold mine in Tanzania) used the Coarsened Exact Matching (CEM) approach, which matches the social, economic, and environmental risk-factor characteristics of households in treated and control groups. It also used a linear and logistics regression using CEM Weight to obtain robust treatment effects. The results show that health outcomes (proxied by stunting rate) were significant within 10km of the nearby mine. The probability of a child in the treated group being stunted was 0.226 greater than for a child with similar social, economic and environmental risk factors in the control group. Moreover, the OLS regression suggested similarly that the children in the treated group had height-for-age Z-scores (HAZ06) of 0.827 less than for similar children in the ...
This study evaluates the environmental performance of large gold-mining operations by applying a ... more This study evaluates the environmental performance of large gold-mining operations by applying a by-production model that specifies emission-generating technology, while incorporating a four-way error approach that captures mine-size heterogeneity, transient and persistent technical efficiency, and random errors. We applied a true random effects model (TREM), and a simulated maximum likelihood estimator (SMLE) based on the generalised true random effects model (GTREM). Firm-level data from 2009 to 2018 were used; the results show the presence of environmental and technical inefficiencies. Moreover, each inefficiency was decomposed into transient and persistent inefficiencies. The overall environmental performance of the mines in developing countries is low (66%) compared to other sectors, which indicates that there could be structural rigidities, poor environmental policies and regulations, poor enforcement, or any combination of the three. We also found robust empirical evidence that between 2009 and 2018, on average, gold-mining firms neither strongly increased nor strongly decreased their transient or their persistent technical and environmental efficiency. Besides, firms with high technical efficiency simultaneously have high environmental efficiency, which suggests that promoting high environmental efficiency will also promote high technical efficiency.
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Papers by Isaiah Magambo