Attitudes towards and acceptance of agricultural biotechnology, which involves inserting genes that carry new traits into existing varieties, has been subject to much debate. This special issue aims to address several gaps in the literature on genetically modified (GM) technology in agriculture. Some of the papers in the issue address the economic and health aspects of genetic modification in agriculture while others examine consumers’ attitudes towards GM products, and the marketing and labeling of GM products.

We use aggregate data to estimate supply, price, land-use, and greenhouse gas impacts of genetically engineered (GE) seed adoption due both to increased yield per hectare (intensive margin) and increased planted area (extensive margin). An adoption model with profitability and risk considerations distinguishes between the two margins, where the intensive margin results from direct ‘gene’ impacts and higher complimentary input use, and the extensive margin reflects the growing range of lands that become profitable with the GE technology. We identify yield increases from cross-country time series variation in GE adoption share within the main GE crops – cotton, corn and soybeans. We find that GE increased yields 34 per cent for cotton, 12 per cent for corn and 3 per cent for soybeans. We then estimate the quantity of extensive margin lands from year-to-year changes in traditional and GE planted area. If all production on the extensive margin is attributed to GE technology, the supply effect of GE increases from 5 per cent to 12 per cent for corn, 15 per cent to 20 per cent for cotton, and 2 per cent to 40 per cent for soybeans, generating significant downward pressure on prices. Finally, we compute ‘saved’ lands and greenhouse gases as the difference between observed hectarage per crop and counterfactual hectarage needed to generate the same output without the yield boost from GE. We find that altogether, GE saved 13 million hectares of land from conversion to agriculture in 2010, and averted emissions are equivalent to roughly one-eighth of the annual emissions from automobiles in the US.

We use farm survey data and a damage control framework to analyze impacts of Bt cotton on yields and pesticide use in Pakistan. We also derive optimal levels of pesticide use with and without Bt, taking into account health and environmental externalities. This has not been done previously in the literature. Conventional cotton growers suffer from significant insect crop damage; they underuse pesticides from a profit-maximizing perspective. Yet, the picture is reversed when externalities are also considered. The social optimum of pesticide use is much lower than the private optimum, and both optima are lower with Bt than without this technology. Bt controls pest damage more effectively. Hence, yields on Bt farms are about 20 per cent higher in spite of lower pesticide use. Large pest damage is a typical phenomenon in developing countries. In such situations, Bt can contribute to productivity growth, while reducing pesticide applications and associated negative externalities.

Vitamin A enriched rice (Golden Rice) is a cost-efficient solution that can substantially reduce health costs. Despite Golden Rice being available since early 2000, this rice has not been introduced in any country. Governments must perceive additional costs that overcompensate the benefits of the technology to explain the delay in approval. We develop a real option model including irreversibility and uncertainty about perceived costs and arrival of new information to explain a delay in approval. The model has been applied to the case of India. Results show the annual perceived costs have to be at least US$199 million per year approximately for the last decade to explain the delay in approval of the technology. This is an indicator of the economic power of the opposition towards Golden Rice resulting in about 1.4 million life years lost over the past decade in India.

This paper analyses the factors inducing retailers to adopt genetically modified (GM)-free private standards, using information on 44 retailers operating in 54 countries. Retailers are distinguished between those not using GM ingredients and those using ingredients which are potentially GM in their private label products. Results from a binary response model show that many of the drivers highlighted in the empirical literature, such as historical factors, communication infrastructure and sectorial conditions, affect the likelihood of adopting GM-free private standards. Moreover, we test additional hypotheses from the political economy of standards formation and of mass media. Key results show that a higher share of government-oriented public media reduces the probability of adopting GM-free private standards, while different genetically modified organism public standards between home and operating countries increase this probability.

Previous research has found that presenting consumers with information regarding multi-attributes of a product tends to reduce the product's overall evaluation relative to a situation wherein only one attribute is presented. We find that the same phenomenon also holds for consumers' perceptions regarding attributes associated with genetically modified (GM) products. When given information on health (nutrients) and water use of certain crops, consumers reduce their quality perceptions compared to the situation wherein they are given only health or only water use information. In addition to replicating the findings on this phenomenon in another product category – that of GM products – we extend the theory by showing that multi-attribute information results in lower perceptions of attributes in addition to deflated total evaluation. This finding provides another explanation of consumers' resistance to GM products beyond risk and negative predisposition. Our findings can be used to guide policy makers in designing educational campaigns.

Food labelling is costly. Food labelling is often demanded with the introduction of new food products such as genetically modified (GM) food. If consumers do not have trust in the label, scarce resources are wasted. This paper investigates factors affecting the trust in food labels among Ugandan consumers. The results suggest that older, less-educated individuals of smaller household sizes and with trust in government institutions have more trust in food labels. Other factors were also found to be important. The government has to consider those differences in consumer trust when designing a GM labelling policy.