Current and recent projects
The Economics of Biodiversity Additionality (2022-25)
(1) ‘Spatial-economic determinants of forest regeneration in the Amazon’ (with Lykke Andersen, Ben Balmford, Sabrina Eisenbarth, Ben Groom, Ville Inkinen, Fabiana Karina, Sarah Meier, Lorenzo Sileci, and Diana Weinhold)
(2) ‘The paradox of conservation policy layering’ (with Ben Groom and Lorenzo Sileci)
Funded by the Natural Environment Research Council, funding call: ‘Economics of Biodiversity’.
'Forest co-management and poverty-environment traps' (2022-)
(with Jessica Meyer)
Implemented globally since the 1990s, co-management involves the devolution and transfer of common-pool resource rights from governments to rural communities. In practice, this process often also involves efforts to improve livelihoods and reduce poverty via sustainable resource use. Quantitative empirical evidence to date suggests mixed effects with respect to forest co-management’s impacts on poverty and resource conservation, including in Sub-Saharan Africa. Our study seeks to contribute to the literature with a better understanding of the behavioural channels through which co-management influences poverty and forests and the mechanisms by which co-management changes behaviour underlying outcomes. With a focus on Malawi, we construct a household panel dataset and empirically evaluate the poverty and forest impacts of the national-level Improved Forest Management for Sustainable Livelihoods Programme (IFMSLP) two and five years after it ended, in 2014. The results from application of a differences-in-differences framework to our data suggest that the IFMSLP increased rather than reduced household poverty, as measured by incomes, assets and a measure of food security, the Food Consumption Score. The observed increase in poverty is larger in 2016 than in 2019, suggestive of a dissipation in impact over time. The IFMSLP had no overall effect on deforestation. To understand how and why co-management increased poverty, we test the hypothesis that co-management's focus on resource extraction, coupled with fewer alternative livelihoods, is associated with lower labour productivity and hence, worsening poverty. The increase in poverty is found to be strongly correlated with fewer livelihoods and a dependence on agriculture and firewood collection. To locate the source of the poverty effect, we examine spatial variation in our results with a comparative empirical analysis of the Central and South regions. The poverty increase originates in the Central region where we also observe an increase in deforestation. The magnitude of deforestation is larger in 2019 than in 2016. The results of our regional analysis are suggestive of a poverty-environment trap, with increasing poverty among resource-dependent households in 2016 potentially leading to greater incentives to deforest in 2019.
‘The heterogeneous impacts of drought intensity on crop yields in a warming world’ (2021-)
(with Dalia Fadly and Francisco Fontes)
Freshwater is a critical input to agricultural production, the biggest user of water globally. Yet, water scarcity threatens to constrain the future expansion of food supplies. With global warming, droughts are projected to be more frequent, intense, and longer lasting. Addressing water scarcity in the agricultural sector has historically focused on expanding water supply via the building and expansion of irrigation systems. The expansion of irrigation in water-stressed, drought-prone cultivated areas is potentially an effective and sustainable adaptive measure to maintain, or even increase, productivity. Previous research on the benefits of irrigation for productivity and drought mitigation has been conducted at a relatively aggregate level, masking the extent of spatial heterogeneity in irrigation’s realised or potential benefits. We exploit spatial heterogeneity in district-level data collected in India between 1966–2011 to empirically evaluate the extent to which the expansion of irrigation under India’s Interlinking Rivers (ILR) mega project is likely to mitigate the impacts of drought intensity on rice and millet yields. We first show that for both crops there is large spatial heterogeneity in the impacts of drought intensity on yields and that the extent of variation is increasing with greater drought intensity. Negative yield impacts due to higher temperature are offset by greater irrigation coverage, particularly when drought is severe. However, targeted districts in the Peninsular component of the ILR have estimated lower impacts when irrigation is expanded than districts located in the Himalayan component.
[working paper, version April 2023, under revision]
(with Ben Groom, Lorenzo Sileci and Steve Langton)
The post-2020 Global Biodiversity Framework proposes to address biodiversity decline by expanding areas under conservation. Biodiversity conservation in agricultural landscapes, the world’s predominant land use, could involve sparing, or setting aside, agricultural land from production, implying biodiversity-food trade-offs. Employing bird species and agricultural data, we undertake a novel empirical analysis of such trade-offs on a set-aside scheme implemented in England between 1992-2007. Expanding set-aside increases bird species abundance and richness by, respectively, 1.2-2.1% and 0.7-0.9%, but has no impact on diversity (Shannon Wiener index). These effects are discontinuous, subject to thresholds in set-aside areas. A minimum 3% of agricultural land set aside is required for a positive effect on biodiversity while 13% of agricultural land generates a 15-25% and 30-35% increase in abundance and richness, respectively. Estimates of short- and long-run effects show that impacts are larger in the long-run. Expanding set-aside is also associated with a 10-17% decline in cereal output, with weak evidence of an attenuating land-sparing effect on yields. Our results suggest that although biodiversity-food trade-offs are likely in high-yield agricultural landscapes, such as those in England, the risk of a reduction in food supply could be minimized in settings where there is still scope for intensification.
(with Ben Groom and Lorenzo Sileci)
International initiatives for reducing carbon emissions from deforestation and forest degradation (REDD+) could make critical, cost-effective contributions to tropical countries’ nationally determined contributions (NDCs). Norway, a key donor of such initiatives, had a REDD+ partnership with Indonesia, offering results-based payments in exchange for emissions reductions calculated against a historical baseline. Central to this partnership was an area-based moratorium on new oil palm, timber, and logging concessions in primary and peatland forests. We evaluate the effectiveness of the moratorium between 2011 and 2018 by applying a matched triple difference strategy to a unique panel dataset. Treated dryland forest inside moratorium areas retained, at most, an average of 0.65% higher forest cover compared to untreated dryland forest outside the moratorium. By contrast, carbon-rich peatland forest was unaffected by the moratorium. Cumulative avoided dryland deforestation from 2011 until 2018 translates into 67.8 million to 86.9 million tons of emissions reductions, implying an effective carbon price below Norway’s US$5 per ton price. Based on Norway’s price, our estimated cumulative emissions reductions are equivalent to a payment of US$339 million to US$434.5 million. Annually, our estimates suggest a 3 to 4% contribution to Indonesia’s NDC commitment of a 29% emissions reduction by 2030. Despite the Indonesia–Norway partnership ending in 2021, reducing emissions from deforestation remains critical for meeting this commitment. Future area-based REDD+ initiatives could build on the moratorium’s outcomes by reforming its incentives and institutional arrangements, particularly in peatland forest areas.
Related commentary: 'Halting deforestation by 2030 – lessons from Indonesia?'