Dennis Engist - Research

Job Market Paper

The merits of unilateral environmental trade policies: evidence from fisheries

Dennis Engist

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Unilateral environmental trade policies allow single actors to independently enact environmental protection standards beyond their borders. However, it is unclear under which conditions such policies achieve their goal, as they can be rendered ineffective by trade diversion. In this study, I examine this question at the example of the European Union policy against illegal, unreported and unregulated fishing, which is designed to enforce global fisheries standards through a system of warnings (yellow cards) and trade sanctions (red cards). I estimate the effect of yellow and red cards on trade and marine capture production. I find that both types of cards lead to reductions in exports to the EU, but no evidence of trade diversion. Meanwhile, I find a temporary reduction in catch following cards cards, which suggests that production rather than trade is adapted. I also identify a shift in fisheries production that is persistent after the cards are lifted. Specifically, I observe a reduction in the number of active fisheries, which points to the policy having lasting impacts beyond trade. This study provides evidence of a unilateral environmental trade policy that is effective in enforcing environmental standards and offers lessons for similar policies.

The value of biodiversity: evidence from migratory birds

Frederik Noack, Dennis Engist, Ashley Larsen

SSRN Working Paper

We estimate the economic value of biodiversity by estimating the value of pest control services provided by migratory birds to U.S. agriculture and forestry. Exploiting exogenous variation in migratory bird returns driven by winter habitat conditions in South America, we find that a 10% decline in avian biodiversity reduces crop revenues by 1.1% and increases forest pest outbreaks by up to 1.2%. We find that the elasticity of substitution among bird species is high in agricultural landscapes and lower in forests, implying that ecosystem service provision in agriculture depends more on the total abundance of birds, while in forests it depends more on the number of species. These findings identify biodiversity as a productive input and highlight cross-border externalities from environmental degradation.

The impact of genetically modified crops on bird diversity

Dennis Engist, Laura Melissa Guzman, Ashley Larsen, Trevor Church, Frederik Noack

Nature Sustainability

Biodiversity provides essential ecosystem services to agriculture, including pest control and pollination, yet it is declining at an alarming rate, largely due to the agricultural sector. The introduction of genetically modified (GM) crops in the United States marked a major transformation of agricultural production as over 90% of US corn, soybean, and cotton areas are now planted with GM varieties. This shift in crop cultivation has substantially altered crop management practices, most notably the types and quantities of pesticides used. Despite the magnitude of these changes, the impact on biodiversity is still poorly understood. Here, we estimate the causal impact of GM crops on bird diversity in the United States and compare bird communities through time in areas with different levels of exposure to GM crops. We find that insectivorous birds benefit from GM crop adoption and that this benefit is largest in cotton. In contrast, herbivorous birds weakly decrease with GM crop adoption. Thus, while GM crop adoption has a small positive effect on overall abundance of birds, the effect is heterogeneous across species groups, with potentially important consequences for bird community composition and associated ecosystem services in agricultural systems.

Environmental impacts of genetically modified crops

Frederik Noack, Dennis Engist, Josephine Gantois, Vasundhara Gaur, Batoule F Hyjazie, Ashley Larsen, Leithen K M’Gonigle, Anouch Missirian, Matin Qaim, Risa D Sargent, Eduardo Souza-Rodrigues, Claire Kremen

Science

Genetically modified (GM) crops have been adopted by some of the world’s leading agricultural nations, but the full extent of their environmental impact remains largely unknown. Although concerns regarding the direct environmental effects of GM crops have declined, GM crops have led to indirect changes in agricultural practices, including pesticide use, agricultural expansion, and cropping patterns, with profound environmental implications. Recent studies paint a nuanced picture of these environmental impacts, with mixed effects of GM crop adoption on biodiversity, deforestation, and human health that vary with the GM trait and geographic scale. New GM or gene-edited crops with different traits would likely have different environmental and human health impacts.

Agricultural systems and biodiversity: evidence from European borders and bird populations

Dennis Engist, Robert Finger, Peter Knaus, Jérôme Guélat, David Wuepper

Ecological Economics

Countries' agricultural systems have an important impact on biodiversity, for example bird populations. Here, we estimate such impacts by exploiting a natural experiment in the middle of Europe, where there is a naturally homogenous area that is divided into three countries: Switzerland, Germany, and France. These countries have markedly different agricultural systems and policies. Using a methodologically unified and unusually rich bird dataset available across these borders, both for the 2010s and 1990s, we analyze (a) whether there is a clear pattern that bird diversity systematically changes when crossing these borders and (b) whether this has changed over time. To assess bird populations, we focus on Shannon diversity, species richness and number of territories, as well as the individual effect on 29 common bird species. We find that Switzerland has systematically smaller and less diverse bird populations compared to Germany and France, driven entirely by agricultural differences. At the same time, we find that the difference between the countries was considerably more pronounced in the 1990s than in the 2010s. Yet, to reach the bird friendliness of Switzerland's neighboring countries, additional policy effort seems required, for example in the form of targeted agri-environmental payments.