Ryan Abman

Research

Research Areas

My research asks how economic forces — trade liberalization, commodity price shocks, agricultural productivity, and governance institutions — drive deforestation and shape the effectiveness of conservation policy. I use quasi-experimental methods and large microdata sets to study these questions across sub-Saharan Africa, Latin America, and Southeast Asia. A related strand of work examines how environmental provisions in trade agreements affect emissions and land use, and how political accountability influences environmental enforcement.

Environmental Economics Natural Resource Economics International Trade Economic Development Applied Econometrics Political Economy Deforestation Conservation Policy

Working Papers

Agricultural Productivity and Deforestation

with Teevrat Garg, Yao Pan, and Saurabh Singhal

Improving agricultural productivity is vital to anti-poverty and food security goals but can have ecological ramifications. Increasing the relative value of agricultural land may spur deforestation, but factor market constraints paired with improvements in existing land productivity may reduce the demand for clearing forests for agriculture. Leveraging the discontinuity in eligibility for a large agricultural training program, we find that the program reduced deforestation by 14%. The program increased adoption of promoted practices such as manure-use and crop rotation driving higher productivity but no increase in cultivated area. Median estimates suggest that carbon savings alone cover 15% of program costs.
Child Labor Standards in Regional Trade Agreements

with Clark Lundberg, Michele Ruta, and John McLaren · Under revision, Review of Economics and Statistics · NBER Working Paper #30908

We study the effects of child labor standards in Regional Trade Agreements (RTAs). We develop a general equilibrium model of child labor in an economy open to trade, then empirically investigate the effects of these clauses using harmonized survey microdata from 101 developing countries. RTAs without child-labor bans reduce child employment and increase school enrollment, particularly for older children (ages 14–17). Perversely, child labor bans in RTAs increase child employment among 14–17 year olds and decrease school enrollment for both younger and older children.
Strengthening International Environmental Agreements through Trade Policy

with Clark Lundberg and Daniel Szmurlo · Under revision, Journal of Environmental Economics and Management · World Bank Policy Research Working Paper 10319

We study the impact of linking trade liberalization to international environmental agreements. We develop a stylized model showing that trade liberalization itself can encourage participation in environmental treaties, and that directly linking trade policy to environmental agreements can further strengthen compliance. We test these predictions empirically in the context of the Montreal Protocol, the landmark international agreement regulating ozone-depleting substances.
Electoral Accountability, Blacklisting, and Deforestation in the Brazilian Amazon

Local political authority (formal or informal) over natural resources may create rents for politicians. The political decision to use or allocate resources involves balancing private rents with reelection prospects. I examine the case of deforestation in Brazil and a presidential decree granting the federal government the authority to punish counties that failed to limit total deforestation within their borders. This collective punishment aimed to generate pressure on local politicians to slow deforestation. Using binding term limits as a source of variation in reelection eligibility, I find eligibility has no effect on deforestation prior to the decree. After the decree, reelection eligible mayors reduced annual deforestation 10% more than mayors ineligible for reelection. These findings are consistent with the equilibrium outcome of a lobbying model. Policies such as sanctions, which target the electorate in order to influence political behavior, may be less effective when politicians are not accountable to voters.

Works in Progress

Land Beyond Borders: Trade Policy and the International Market for Land

with Clark Lundberg, Frederik Noack, and Ana Palacios · USDA/NIFA funded

Since 2000, more than 36 million hectares of land have been acquired by foreign investors for agricultural and natural-resource development across less-developed countries. While such investment may offer prospects for growth, the opaque nature of these acquisitions—and their potential implications for local welfare and the global environment—has raised widespread concern. A central but under-examined issue in this debate is how international economic agreements structure the incentives and protections that facilitate foreign land purchases. This paper investigates how trade agreements shape foreign land acquisitions. Combining bilateral large-scale land transaction data from 1980–2018 with the universe of regional trade agreements (RTAs), we show that RTAs substantially increase foreign land purchases, particularly in agriculture and forestry. These effects are driven mainly by upper-middle-income investor countries. We further find countries facing domestic land scarcity respond more to RTAs and seek investments in countries sharing similar climatic conditions, and that market access to third-party countries amplifies this pattern. RTAs that include investment-protection provisions—such as guarantees against expropriation—produce even larger increases in foreign land acquisitions. Taken together, the results demonstrate that trade policy plays a central role in structuring the global land market through investment, market-access, and resource-access channels.
Trade Liberalization and Human Capital Formation: Child Learning and Child Labor in Peru

with Clark Lundberg, Leah Lakdawala, and Eduardo Nakasone

Trade liberalization can promote long-run growth, but adjustment costs fall unevenly and may affect children's human capital with lasting consequences. We examine how Peru's dramatic unilateral liberalization efforts affected human capital, exploiting local labor market exposure to import tariff cuts and combining household surveys with administrative records on test scores and enrollment. We document a stark trade-off between the quantity of schooling and the quality of learning. Greater exposure to import competition increased public primary school enrollment and attendance, yet learning outcomes deteriorated: exposed districts experienced a decline in average math scores. We trace these divergent outcomes to countervailing income and substitution effects. While the decline in returns to low-skill labor increased the relative value of schooling, negative shocks to household income forced children to combine education with employment. Finally, we document a substitution from private to public schooling driven by income constraints, which mechanically raised average private school scores via compositional changes. Our results highlight that trade reforms can expand school access while simultaneously eroding learning quality, a cost standard enrollment metrics fail to capture.
Frontier Settlement and Agricultural Migration in Latin America

with Clark Lundberg and E. Klotz

Cross-border agricultural land acquisitions and frontier settlement are reshaping forested regions in Latin America. Low German Mennonite colonies represent a distinct form of transnational agrarian expansion—large, contiguous land purchases followed by the rapid development of commercial-scale agriculture—that has accelerated settlement in remote forest frontiers. We combine spatially explicit data on 105 Mennonite colonies established across Latin America after the year 2000 with annual satellite measures of forest loss, biomass carbon, biodiversity, and nighttime luminosity. We exploit quasi-experimental variation in establishment timing and locations of Mennonite settlements to plausibly identify the causal impacts of these frontier settlements on the local environment, ecology, and economic development. Frontier settlements lead to very large and significant forest loss with substantial ecological and environmental costs. We find no evidence of any positive development spillovers to local communities. Our findings highlight the ecological consequences of cross-border agricultural settlement in frontier regions.
Democratic Transitions and Deforestation in Indonesia

with Clark Lundberg

Local democratic institutions have important implications for natural resource management, especially when extraction is associated with environmental externalities. We study the effects of a transition to direct local democratic institutions on natural resource management using a political agency model with electoral competition. Our model of political decentralization suggests that this transition will lead to an increase in local extraction with greater negative externalities. In localities with weak electoral competition, agency costs are higher and the transition leads to resource rent capture by corrupt officials with illegal extraction in protected areas. In localities with strong competition, increased extraction is through legal channels and is associated with local increases in welfare. We use Indonesia's transition from locally-appointed leaders to locally-elected leaders as a natural experiment to study forest management. The timing of local elections varied district-to-district both across and within provinces and was determined by the local appointment cycles before the transition. Using high-resolution satellite data on forest cover loss, we apply a difference-in-differences approach and find significant evidence that district-level deforestation increased following direct local elections. In districts with weak electoral competition, this deforestation appears consistent with resource rent capture by corrupt officials driven by illegal logging in protected areas and no commensurate increase in economic development. In contrast, deforestation in districts with high electoral competition appears to be driven by local development.
Risk, Resilience, and Forests: The Pro-Environmental Impact of Agricultural Insurance

with Jeffrey Pagel

In the absence of well-functioning insurance markets, extreme weather shocks tighten liquidity constraints and shift land use decisions toward strategies that increase pressure on forested land. This paper studies whether agricultural insurance can weaken the link between climate shocks and forest loss. Using a stacked triple-differences design that exploits variation in typhoon exposure and the staggered rollout of two large-scale government insurance programs across Philippine municipalities, we find that typhoons generate sharp increases in forest loss in uninsured municipalities while insured municipalities experience no such increase. Household-level evidence points to a financial distress mechanism, where typhoon exposure generates increases in debt burdens and declines in income among uninsured households while insured households see agricultural income rise and loan payments fall substantially. Translating the changes in forest cover into carbon flows, the carbon co-benefit of the program exceeds government expenditure by a factor of at least 7.7 and as much as 84 depending on the measure of program cost, with a breakeven carbon price ranging from $2.3 to $24.7 per tonne CO2, suggesting that agricultural insurance programs generate substantial ecological co-benefits that are typically overlooked in program evaluation.
Development and land use change from recreational tourism

Tourism accounts for roughly 10 percent of global GDP and one in ten jobs worldwide. Natural amenities can attract recreational visitors, yet information frictions may prevent many locations from realizing tourism-driven gains. This paper studies how reducing information frictions affects local development and environmental outcomes, exploiting the staggered listing of surf breaks on a prominent online surf directory as shocks to the information set of potential tourists. Using nearly 400 breaks listed between 2003 and 2017 across 69 countries, I estimate event-study difference-in-differences models linking these listings to satellite-derived nighttime lights and remote-sensing measures of forest loss. Economic activity within 2 km of a surf break increases by about 8 percent following listing, while forest loss shows no detectable average effect. Effects are heterogeneous across countries, consistent with differences in baseline accessibility and institutional context. The results suggest that digital platforms can shift tourism demand toward remote coastal areas and generate economically meaningful local development, while environmental impacts are heterogeneous across settings.
Forest Resources and Clean Energy Transition

with Clark Lundberg · International Growth Centre funded
Saline Lakebed Emissions and Infant Health

with Eric C. Edwards, M. Korb, and Danae Hernandez-Cortes

Publications

Published Work

2026

"The Limits of Cross-Border Environmental Policies: Trade Diversion as Leakage." With Hattie Jenkins and Clark Lundberg. Journal of Environmental Economics and Management.

Global environmental externalities are one of the most pressing policy challenges of the modern era. Unilateral policy options to address global externalities are limited, however, by sovereignty and a general difficulty in achieving environmental objectives across national borders. We study an emerging trade policy tool used in cross-border environmental policies—environmental standards for imports—using a European Union program aimed at mitigating illegal timber harvesting in tropical timber exporting countries. Through bilateral agreements with partner countries, the program established de facto import restrictions through supply chain transparency and certification requirements on forest products. We find that the policy led to a diversion of partner country exports away from the EU towards other markets, particularly in Asia, and had no discernible impact on reducing forest loss. Our findings highlight the role that trade diversion can play as a leakage mechanism in such cross-border environmental policies.
2025

"Water, Dust, and Environmental Justice: The Case of Agricultural Water Diversions." With Eric C. Edwards and Danae Hernandez-Cortes. American Journal of Agricultural Economics, Vol. 107, Issue 4, pp. 1041–1058.

KPBS CNS

Water diversions for agriculture reduce ecosystem services provided by saline lakes around the world. Exposed lakebed surfaces are major sources of dust emissions that may exacerbate existing environmental inequities. This paper studies the effects of water diversions and their impacts on particulate pollution arising from reduced inflows to the Salton Sea in California via a spatially explicit particle transport model and changing lakebed exposure. We demonstrate that lakebed dust emissions increased ambient concentrations and worsened environmental inequalities, with historically disadvantaged communities receiving a disproportionate increase in pollution. Water diversion decisions are often determined by political processes; our findings demonstrate the need for distributional analysis of such decisions to ensure equitable compensation.
2024

"The Effectiveness of Environmental Provisions in Regional Trade Agreements." With Clark Lundberg and Michele Ruta. Journal of the European Economic Association, Vol. 22, Issue 6, pp. 2507–2548.

Trade liberalization can spur environmental degradation. Concerns over these adverse impacts have led to a debate over the need for environmental provisions in regional trade agreements (RTAs); however, the effectiveness of such provisions is unknown. In this paper, we provide new plausibly causal evidence that environmental provisions are effective in limiting deforestation following the entry into force of RTAs. We exploit high resolution, satellite-derived estimates of deforestation, and identify the content of RTAs using a new dataset with detailed information on individual provisions. Accounting for the potential endogeneity of environmental provisions in RTAs, we find that the inclusion of specific provisions aimed at protecting forests and/or biodiversity almost entirely offsets the net increases in forest loss observed in similar RTAs without such provisions. The effects are particularly strong in tropical, developing countries with greater biodiversity. The inclusion of these provisions limits agricultural expansion and agricultural trade.
2024

"Contracting, Market Access and Deforestation." With Clark Lundberg. Journal of Development Economics, Vol. 168.

We study the impacts of market access on forest loss in Ghana through a program designed to increase smallholder participation in oil palm commodity markets. Improved market access is facilitated through production contracts in which smallholders receive credit to establish production, a guaranteed price and quantity for the contract duration, and output pickup at the village. Using a variety of difference-in-differences approaches, we find substantial increases in forest loss in targeted villages following the introduction of the contracting program. The findings suggest that the ecological impacts of reforms to market access may be sizeable.
2023

"Resource Development and Governance Declines: The Case of the Chad–Cameroon Petroleum Pipeline." With Gabrial Longbrake. Energy Economics, Vol. 117.

In this paper, we study the effects of the Chad–Cameroon Petroleum Development and Pipeline Project that allowed Chad to begin producing and exporting oil. The project was financed under heavy restrictions by the World Bank in an attempt to avert the resource curse. The majority of revenue from the resource was to be directed back into development programs with minimal government discretion. Using synthetic control matching and synthetic difference in differences, we find that oil production had immediate and persistent negative impacts on the quality of governance, increased GDP per capita, but had little lasting effects on measured development outcomes such as infant mortality and health spending. Our findings offer new empirical evidence for the political resource curse and suggest that the World Bank's experiment to impose rules over management of resource rents was not sufficient to ensure widespread benefits from natural-resource wealth.
2022

"Maize Price Volatility and Deforestation." With Clark Lundberg. American Journal of Agricultural Economics, Vol. 104, Issue 2, pp. 693–716.

We develop a model of deforestation using a real option on agricultural land conversion and establish an important link between agricultural commodity price volatility and forest loss. Higher price volatility of staple commodities increases incentives to delay land conversion and is associated with lower levels of deforestation. Using satellite-derived estimates of local deforestation and high-frequency local maize prices across a panel of market catchments across 26 countries in sub-Saharan Africa, we find strong empirical evidence that maize price volatility is negatively associated with forest loss. Our findings are driven by catchments in biomes that are relatively well-suited to maize production. Instrumenting for changes in price levels and price volatility with spatially explicit temperature and rainfall anomalies yields results consistent with our main approach. The findings highlight important tensions between agricultural price stabilization policies, conservation efforts, and environmental externalities.
2022

"Border Walls and Crime: Evidence from the Secure Fence Act." With Hisham Foad. Eastern Economic Journal, Vol. 48, Issue 2, pp. 167–197.

🏆 Eckstein Award — Best 2021–22 Paper The Crime Report CATO Research Brief

Despite a lack of rigorous empirical evidence, reduced crime is often touted as a potential benefit in the debate over increasing border infrastructure (i.e., border walls). This paper examines the effect of the Secure Fence Act of 2006, which led to unprecedented barrier construction along the US–Mexico border, on local crime using geospatial data on dates and locations of border wall construction. Synthetic control estimates across twelve border counties find no systematic evidence that border infrastructure reduced property or violent crime rates in the counties in which it was built. Further analysis using matched panel models indicates no effect on property crime rates and that observed declines in violent crime rates precede barrier construction, not the other way around. Taken together, this paper finds that potential crime reductions are not a compelling argument toward the benefits of expanding border infrastructure.
2020

"Agricultural Productivity and Deforestation: Evidence from Input Subsidies and Ethnic Favoritism in Malawi." With Conor Carney. Journal of Environmental Economics and Management, Vol. 103.

This paper studies the underlying relationship between agricultural productivity and deforestation by analyzing the impacts of a large fertilizer and seed subsidy program in Malawi. In the absence of well-defined subsidy eligibility criteria, we demonstrate that areas with a high proportion of individuals of the same ethnicity as the president received more subsidized fertilizer and deforested less compared to areas with other predominant ethnicities. We provide evidence that subsidized fertilizer increased yields and reduced pressure to expand agriculture and that the findings are not confounded by increases in public sector employment or other public assistance programs. The results suggest that policies aimed at increasing small-scale agricultural productivity may have positive environmental spillovers.
2020

"Land Rights, Agricultural Productivity, and Deforestation." With Conor Carney. Food Policy, Vol. 94.

This paper studies the relationship between land tenure for smallholder agriculture and deforestation. We combine high resolution satellite data on deforestation with rich household and commune-level, biannual panel data from Vietnam. We study two margins of tenure security, whether a household has any land title (extensive) and the share of a household's land held in title (intensive). Using a household-fixed effects model, we find the increases in crop production and land investment associated with holding land title are driven by the intensive margin. We then aggregate the survey data to the commune-level and find evidence that marginal increases in extensive tenure (share of households with any land title) increase deforestation holding constant the average intensive tenure (average share of land held in tenure among those with land title). We find some evidence that increasing the intensive margin of tenure (holding constant the extensive tenure) decreases deforestation. These results present a more nuanced view of the tenure-deforestation relationship than is prevalent in the existing literature.
2020

"Does Free Trade Increase Deforestation? The Effects of Regional Trade Agreements." With Clark Lundberg. Journal of the Association of Environmental and Resource Economists, Vol. 7, No. 1, pp. 35–72.

This paper provides new, global evidence on the relationship between trade liberalization and deforestation. Using event studies around the enactment of regional trade agreements (RTAs) on a panel of 189 countries from 2001 to 2012, we find a large and statistically significant increase in deforestation over the 3 years following the enactment of an RTA, which coincides with an increase in agricultural land conversion. The findings are robust to a variety of controls and fixed effects. The results on deforestation and agricultural land expansion are driven by developing countries in the tropics, suggesting that trade liberalization not only increases net deforestation but may also shift deforestation into ecologically sensitive locations. We find no evidence that these effects are driven by increases in timber harvest. Our results suggest that trade liberalization efforts should be accompanied by policies to direct agricultural land expansion away from forests and sensitive habitat regions.
2018

"Rule of Law and Avoided Deforestation from Protected Areas." Ecological Economics, Vol. 146, pp. 282–289.

Global efforts to protect biodiversity and slow deforestation rely heavily on the establishment of protected areas; land set aside that cannot be deforested or developed. This paper studies the macro-level relationship between rule of law and variation in avoided deforestation from protected areas. Using recent global satellite data from 2000 to 2012, I estimate the country-level avoided deforestation of protected areas established in this period via nearest-neighbor matching. I then use weighted least-squares regressions to explain country-level variation in estimated avoided deforestation as a function of a country's governance characteristics as well as other country-level controls. Across 71 countries in this study period, protected areas were more effective in countries with higher levels of corruption control and protection of property rights, protected areas were more effective in more democratic countries, and there appears to be no relationship between political stability and avoided deforestation from protected areas.
2013

"The Underground Economy of Fake Antivirus Software." With Brett Stone-Gross, Richard A. Kemmerer, Christopher Kruegel, Douglas G. Steigerwald, and Giovanni Vigna. Economics of Information Security and Privacy III.

Press: The Economist · Krebs on Security

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