1 Introduction

The Green Revolution was an epochal event that had an enormous impact on global hunger and agricultural development. It had a significant influence on the development trajectory of numerous countries, particularly those in Asia. Countries that were desperately food insecure in the 1960s have become middle-income emerging economies today, some rising rapidly toward high-income status. It is hard to imagine what the developing world would have looked like had the Green Revolution not happened. Despite the success, food insecurity continues to daunt the global community. The number of hungry and malnourished continue to be stubbornly high. A large share of the rural population across the developing world, particularly in Sub-Saharan Africa and South Asia, continues to subsist on low productive agricultural systems and live in poverty. There are incessant calls for donor and national government investments to emulate the Green Revolution experience.

As we look toward future investments in agricultural productivity growth in the developing world, it is important to consider the lessons from the Green Revolution. The Green Revolution led to rapid productivity growth, but only for a small set of crops and for favorable agroclimatic environments. Its productivity impacts on the marginal environments were limited. Small farm productivity growth transformed Asian economies, but Sub-Saharan Africa did not see similar benefits. Even in countries that were considered Green Revolution successes, inter-regional differences in productivity and rural poverty persisted. We saw significant progress in hunger reduction, but micronutrient malnutrition persists across the developing world. Productivity growth in the big three staples—rice, wheat, and maize—led to the crowding out of traditional staples, such as millets, and other micronutrient-rich crops. The environmental consequences of the Green Revolution are well known, but corrective action has been limited. The persistence of Green Revolution-era agricultural policies has dampened farm-level incentives for adopting sustainable intensification practices.

This essay presents a brief synthesis of the lessons learned from the Green Revolution, both positive and negative, and explores options for the way forward. I draw on my numerous papers on the Green Revolution, with my 2012 Proceedings of the National Academy of Sciences (PNAS) paper as a starting point. Interested readers can get further details on the arguments presented from the papers listed in the references. This chapter starts with a presentation of the positive impacts of the Green Revolution, followed by the limits to its success, and ends with a discussion on the way forward that incorporates the lessons learned.

2 Positive Impacts of the Green Revolution

2.1 Impact on Productivity and Food Prices

The rapid increase in agricultural output resulting from the Green Revolution came from an impressive increase in yields per hectare. Between 1960 and 2000, yields for all developing countries rose 208% for wheat, 109% for rice, 157% for maize, 78% for potatoes, and 36% for cassava. Developing countries in Southeast Asia and India were the first to show the impact of the Green Revolution varieties on rice yields, with China and other Asian regions experiencing stronger yield growth in the subsequent decades. Similar yield trends were observed for wheat and maize in Asia. Analysis of agricultural total factor productivity (TFP)Footnote 1 finds similar trends to the partial productivity trends captured by yield per hectare. For the period 1970–1989, the change in global TFP for agriculture was 0.87%, which nearly doubled to 1.56% in 1990–2006 (Pingali 2012). Widespread adoption of Green Revolution technologies led to a significant shift in the food supply function, contributing to a fall in real food prices.

The transformation of Asia from a desperately food-deficit continent to one that is food self-sufficient and, in the case of some countries, achieving a food exporter status, is a well-known story. However, it is also important to remember that a monumental change the Green Revolution ushered in was eradicating famine in Asia. Famines had taken a toll of 80.3 million lives between 1900 and 1969. Between 1970 and 2016, the widespread mortality owing to food shortages declined to 9.2 million (Pingali and Abraham 2022). Asia saw the highest fall in mortality, where the last famine due to non-political reasons was the 1974 Bangladesh famine. The fact that the Green Revolution made famine history in Asia is not appreciated as much as it ought to be.

The Green Revolution-led technological change and investments led to smallholder productivity boosts, significant income growth, and massive poverty reduction in most Asian countries, kick-starting a structural transformation process. Along with the declining share of agriculture in economic output and employment, structural transformation also ushered in rising urbanization; increasing urban economic activity, driven by the industry and services sectors; income growth; and a drop in fertility rates. Many of the emerging economies of Asia today were low-income agrarian economies during the 1960s and used agriculture as an engine of growth and poverty reduction. Current divergence in the levels of economic development across Asian countries can be largely explained by their initial investments in their agricultural sectors, long-term sustained investments in agriculture and rural development, employment generation outside of agriculture, and massive investments in human capital and labor force development at all levels.

3 Where Did the Green Revolution Work?

The success of the Green Revolution was most visible in areas with high population densities and good market infrastructure. The demand for productivity growth through land intensification was highest in these areas. It is therefore not surprising that the earliest adopters of Green Revolution technologies were the densely-populated countries of Asia, such as India, China, and Indonesia. Even within these countries, there was significant intra-regional variation in the adoption of Green Revolution technologies. The irrigated and high rainfall environments quickly assumed the role of the ‘food baskets’ of the country. While the less favorable production environments, such as those with low rainfall, drought-prone areas, and poorer soils, lagged behind and continue to be food-deficit today.

In retrospect, it is not surprising that the focus of the Green Revolution was restricted to three crops—rice, wheat, and maize. These crops had a head start in research and technology investments building on the knowledge stock obtained from the US, Europe, and Japan. Green Revolution innovations, such as short stature and stiff stems, made these crops responsive to intensification inputs, such as irrigation and fertilizer application, and hence, had higher yield potential. Traditional staples, such as millets, sorghum, and tropical tubers, did not have the benefit of drawing on a similar research backlog and were not prioritized during the early phases of the Green Revolution. Although investments during the subsequent decades tried to bridge the research gap between these crops and the big three staples, their productivity and societal welfare impacts were limited.

Additionally, the strength of a country’s national agricultural research system (NARS) was crucial in Green Revolution-led productivity growth. Strong NARS, such as those in China and India, were important conduits for accessing and adapting CGIAR (Consultative Group on International Agricultural Research) technologies and disseminating them to farmers’ fields. NARS capacity focused on the big three staples, and even the strong NARS had weaker capacity in other crops. Sustaining funding support for the NARS during the post-Green Revolution period has been a challenge, and countries that managed to provide continued high-level support saw sustained productivity gains.

Political economy imperatives, especially the management of urban food supplies and food prices, played a major role in enhancing food crop productivity in Asia. Output price supports, input and credit subsidies, and controls on the international food trade played significant roles in providing farmers the incentives for investing in modern high-yielding technologies and management practices.

4 What Were the Limits to the Green Revolution Strategy?

4.1 Technology Was Important But Only with Enabling Policies, Institutions, and Infrastructure Investments

Technological innovation played a pivotal role in the Green Revolution, but technology by itself was not sufficient to ensure success. Infrastructure investments, institutional reforms, and price incentives, all working together, were essential for the rapid adoption of modern technologies and the ensuing growth in productivity and food supplies. Numerous country case studies across Asia have documented the positive food security outcomes of government policies that brought the above four components (innovations, infrastructure, institutions, incentives) into a coherent agricultural policy. The case of Vietnam is particularly illustrative. The country transformed itself from chronic food-deficit status to a major rice exporter by completely overhauling the structure of its production system. Moving away from collective agriculture to freely operating small farms, investments in market infrastructure, and liberalization of food and agricultural commodity trade resulted in an immediate and dramatic transformation of the agricultural sector and kick-started overall economic growth. Vietnam’s agricultural liberalization policies followed closely the earlier and very successful experience of China.

4.2 The Focus on a Limited Set of Crops Crowded Out Diversity in the Food System

A significant unintended consequence of the Green Revolution has been the crowding out of nutrition-rich coarse grains, such as millets, sorghum, and pulses in Asia. Expansion of cultivated area under cereals came at the cost of coarse grains and pulses in many countries. Policies that promoted staple crop production, such as fertilizer and credit subsidies, price supports, and irrigation infrastructure (particularly for rice), tended to crowd out the production of traditional non-staple crops, such as pulses and legumes in India. Coarse grains and pulses are a significant source of critical micronutrients and proteins for the poor in Asia, which has had implications for their nutritional status, as discussed below. By the early 1990s, there was a growing recognition that food security meant more than staple grain self-sufficiency—the need for a balanced diet that included protein, vitamins, and other micronutrients, in addition to calories, was increasingly recognized. At the same time, rising incomes and urbanization led to a rise in demand for diet diversity. Yet, the diversification of production systems away from staple cereals was slow, despite the rising relative prices of non-staples. Policy and structural impediments and a weak private sector limited the supply responsiveness for vegetables and other non-staples.

4.3 Successfully Addressed Calorie Hunger, But Micronutrient Malnutrition Persisted

Nutritional gains of the Green Revolution have been uneven; while overall calorie consumption increased, and there has been a dramatic decline in the incidence of hunger, micronutrient malnutrition persisted, especially among the poor. As discussed above, the narrowing of the food system, making it more concentrated in staples cereals, had an adverse effect on micronutrient supply. Traditional crops that were important sources of critical micronutrients (such as iron, vitamin A, and zinc) were displaced in favor of the higher-value staple crops. Biodiversity loss led to the further narrowing of food diversity (Pingali 2019). For example, intensive rice monoculture systems led to the loss of wild leafy vegetables and fish that the poor had previously harvested from rice paddies in the Philippines. Price effects of such supply shifts further limited access to micronutrients as prices of micronutrient-dense foods rose relative to staples in many places. In India, the increasing price of legumes has been associated with a consequent decline in pulse consumption across all income groups. The calorie-dense nature of the food system has increased the risk of micronutrient malnutrition and contributed to the rise in obesity trends observed across the region today.

4.4 Inter-regional Inequalities in Poverty and Food Insecurity Persisted Despite the Green Revolution Success

The adoption of Green Revolution technologies was also limited to irrigated tracts or regions with high rainfall and low agroclimatic risks, thus leaving out marginal environments and semi-arid areas, creating regional disparities in productivity and income growth. The initial focus on the high-potential environments was undoubtedly the right strategy, given the urgent need to address hunger and food insecurity and the high probability of success building on the scientific progress made in the advanced countries. However, the strategy of replicating the success in the favorable environments by adapting the big three staples to the marginal environments did not provide the intended boost in productivity. A more balanced approach to the marginal environments would have been to focus on the crops that are naturally adapted to those environments, millets, for example. Such a strategy would have required a decentralized approach and relatively more resources but could have resulted in more inclusive growth and enhanced the overall breadth and quality of the food system. People in marginal environments have benefited from the productivity growth in the more favorable environments through lower food prices, migrant labor opportunities, and, to an extent, a reduction in the inter-regional wage gap. However, the welfare gains would have been larger if concurrent efforts were made in investments in human capital and job creation for populations migrating out of the low productive environments.

4.5 Unintended Consequences Undermined the Gains Made

While the Green Revolution was instrumental in averting hunger for millions of people, reducing poverty, and restricting the conversion of additional land for agriculture, it also had other unintended consequences. Environmental degradation resulting from injudicious use of inputs, such as pesticides, fertilizers, and water, and the rise in greenhouse gas (GHG) emissions are well documented. Human health impacts from exposure to pesticides and water contamination due to chemical runoff are also well documented. Negative externalities associated with the Green Revolution were not because of the technology per se but rather its inefficient or improper use. High levels of subsidies for chemical inputs, energy, and water, reduced incentives for being more discriminate in their use. The incentives for learning to be smarter and safer in input use were limited because of distorted input and output prices. True cost accounting of the externalities associated with intensive agricultural production systems is essential for understanding the human welfare costs associated with Green Revolution-era policies and practices.

4.6 Stickiness of Green Revolution-Era Policies Prevented Food System Transformation and Sustainability

The persistence of staple grain fundamentalism in agricultural policy hampers farmer incentives to diversify their production systems and adopt sustainable practices. During the Green Revolution, policies that promoted staple crop productivity growth prioritized rapid increases in the ‘pile of grains,’ with minimal regard for the nutritional tradeoffs and environmental externalities. These policies have been hard to get rid of even after a country has achieved staple crop self-sufficiency and shifted toward diet diversification. The political economy constraints to dismantling antiquated policies that do not address the current demand for food diversity and sustainable food systems have become a major challenge for agriculture and rural development across the developing world.

5 The Way Forward—Policy Agenda for Sustainable Food Systems

This section draws on material presented in Pingali (2018).

The challenges for agricultural development and food security improvement are as great today as they were at the start of the Green Revolution in the 1960s. We have been largely successful in addressing calorie hunger through increased supplies and access to food grains, particularly rice, wheat, and maize. However, we made limited progress in addressing ‘hidden hunger’ caused by inadequate access to micronutrient-rich foods. Transforming food systems to enhance the supply of diversity and nutrient quality is the dominant challenge for developing-country agricultural systems today. Food systems face multiple and concurrent threats, from unabated growth in food demand to intensification pressures on the agricultural resource base and the growing threat of climate-related risks; the complexity of the task ahead is significantly greater than what we faced in the past. Agricultural policy needs to evolve from its traditional focus on productivity improvement for the big three staples toward promoting sustainable food systems that meet the food and nutrition needs of the populations while also driving rural growth.

Unlike in the 1960s, developing countries are on divergent growth trajectories in the twenty-first century, from the least developed countries in parts of Sub-Saharan Africa to the middle-income emerging economies of Asia and Latin America. The pathways to agricultural growth and food security will differ by a country’s economic development stage (Pingali 2010). A ‘one-size-fits-all’ approach used in the past is no longer appropriate in designing agricultural development programs. While the least developed countries face chronic conditions of low productivity and high levels of food insecurity, the emerging economies are rapidly moving toward market integration and agricultural commercialization. Feeding the cities with a diverse food basket provides new growth opportunities for these economies.

A policy agenda for sustainable food systems strives for simultaneous improvements in rural ecosystems’ economic, human health, social, and environmental welfare. Agricultural intensification without increasing negative externalities of agricultural production, such as diminishing biodiversity, increased GHG emissions, and land and water degradation, is important here. In addition, sustainable food systems policies explicitly address the welfare of producers, especially smallholders and the rural poor, and consumers, including considerations of nutrition and food safety. The broad elements of the food and agricultural policy agenda are presented in the following sections.

5.1 Looking Beyond Staple Crop Intensification for the Emerging Economies

Emerging economies face a myriad of challenges that have implications for food system transformation and sustainability. First, rapid growth in incomes, urbanization, and the rise of the middle class lead to the rapid diversification of diets and boost demand for higher-value crops and livestock products. Second, despite significant gains in food supply and food access, inter-regional inequalities in income and nutritional status continue to persist at high levels, especially in the more marginal agroclimatic zones bypassed by the Green Revolution. Third, reversing the negative consequences of the productivity-environment tradeoffs made during the Green Revolution is a major challenge emerging economies face as they try to transition to a more sustainable food system. There is a common thread through all the above issues, and that is a need to reexamine the emphasis given to staple crop production systems in developing countries. Also, there is a need to promote diversity across agro-ecologies and across the food system and enhance resource-conserving technical change.

5.2 Continued Relevance of the Agriculture-Led Growth Strategy for Sub-Saharan Africa

For the low productivity agricultural systems in Sub-Saharan Africa, the Green Revolution strategy of using agriculture as an engine of economic growth and poverty reduction continues to be the ‘best bet’ option. However, unlike in the past, agricultural productivity growth cannot be restricted to the big three staples. It should be inclusive of traditional staples, such as millets, sorghum, and cassava; these crops tend to have higher nutrient content and are better adapted to the agroclimates of the region. Unlike in the case of rice and wheat, the opportunities for technology transfer of these crops to Sub-Saharan Africa from Asia are limited. Africa-based research and development programs are essential and need to be strengthened. Building food system resilience is also a necessary part of the strategy through investments in irrigation infrastructure, promotion of drought-tolerant crop varieties and animal breeds, information services to empower farmers to anticipate and manage crises, and innovations in agricultural insurance. Low-income countries are becoming increasingly integrated into the global food economy, and hence, the sustainability of small farm systems would require them to be competitive and integrated into markets rather than be focused primarily on subsistence production systems.

5.3 R&D for Enhancing Food and Nutrition Security

Agricultural research is often cited as the single-best investment in increasing productivity and reducing poverty in the developing world. Among many investments made in agricultural research during the past five decades, South Asia’s Green Revolution—the doubling of the yields and output of South Asia’s major food staples between 1965 and 1985—is one of the most-cited examples of this high payoff. Continued high levels of investments are needed to enhance the productivity of the major staple grains—rice, wheat, and maize—to meet their rising demand due to population and income growth.

Additionally, productivity gains in traditional staples, such as cassava, millets, barley, and sorghum, that were not the initial focus of the Green Revolution, need to be focused on to improve the diversity of diets and essential micronutrient availability. Such investments could provide new opportunities for growth in the marginal production environments and enhance the supply and accessibility of micronutrient-rich food to the rural poor. There is also an urgent need for R&D investments in making food crops climate-sensitive, especially in marginal production environments.

Biofortification of staple and non-staple food can be a sustainable means of reducing immediate concerns of micronutrient deficiency. Essential micronutrients, such as iron, zinc, and vitamin A, can be accessed through biofortified foods cost-effectively. Biofortification may be an effective approach to remedy deficiencies and ought to be seen as a complement to the promotion of non-staple micronutrient-rich crops.

Research and technology development are also essential for enhancing input use efficiency, focusing on soil fertility, water use efficiency, and pest resistance. Modern information and communication technology (ICT) tools, such as geographic information system (GIS) and remote sensing, could contribute significantly to the sustainable use of inputs. Research on delivery systems for these intrinsically knowledge-intensive technologies is crucial, especially in developing-country smallholder systems. Policy research for effective means of reducing incentive distortions in adopting and using efficiency-enhancing technologies is also essential.

5.4 Promoting Food System Diversity

Despite rising demand, the persistence of Green Revolution-era policies and structural impediments, as well as a weak private sector, limited the supply responsiveness for vegetables, non-staple food, and other sources of food, including livestock and aquaculture. Creating a ‘level policy playing field’ that corrects the historical bias in favor of staple crops would help improve the incentives for diversification of production into non-staple foods. An agricultural policy that is ‘crop-neutral’ (i.e., one that does not favor a particular set of commodities) removes distortions and allows farmers to respond to market signals in making crop production choices (Pingali 2015).

In addition to leveling the playing field, investments in road and transport infrastructure and cold storage systems are required for developing markets for perishable products. Investments in market information systems and farmer connectivity, especially through mobile phones, could significantly cut transaction costs for market participation. Policies promoting food safety should be a priority for upgrading traditional markets and ensuring that human health is safeguarded (Pingali et al. 2015). In addition to reducing foodborne illness and disease, food safety policies can make traditional markets viable places for procurement by modern retail value chains.

Investments in general literacy and specialized training for farmers in meeting quality and safety standards for high-value crops would help integrate smallholders into market value chains. Finally, institutional investments in establishing clear property rights to land and other assets, formalized contractual arrangements that depersonalize market transactions, and access to finance (that is not tied to particular commodities) are essential for diversifying production systems.

5.5 Growth that is Inclusive of Rural Women

Despite having an important role in production, women face high costs in accessing capital, engaging in entrepreneurial activities, and adopting technological inputs and mechanization. Therefore, in many developing countries, women-headed households have lower yields and incomes due to poor access to markets and productive resources, affecting their contributions to agricultural productivity. Closing the gender gap and addressing gender-specific transaction costs and agricultural production constraints is crucial to increasing agricultural productivity and women’s empowerment.

The two major interventions needed to address gender-specific challenges in agriculture are improved access to product markets and labor savings for rural women. Policy initiatives to promote women’s organizations and build capacity to make them self-sustaining are important to tackle gender-specific challenges in production and marketing. Gender-sensitive value chains that make women’s participation in high-value markets easier are essential. As women are often involved in agricultural labor and non-marketed household labor, measures to improve labor efficiency and productivity of women will enable cost savings and free up time. Labor-saving technology through mechanization in agriculture is needed to reduce drudgery.

5.6 Managing Climate Change Impacts

Mitigating the effects of climate change and the need to increase yield simultaneously will pose a major challenge to the growth and development of the agricultural sector. This challenge could be particularly important for crops that are important to the poor, such as millets and cassava. Little is known about the long-term climate impacts on crops beyond the major staples. To offset the current impact of climate change, investment in R&D to promote heat- and drought-resistant crop technologies and infrastructure investment, like micro-irrigation systems, are necessary. Making these technologies easily accessible to smallholders is also crucial. Policy interventions to promote sustainable agricultural intensification are essential to managing the dual challenge of climate change and productivity growth.

Recollections of Professor Keijiro Otsuka

I first met Professor Kejiro Otsuka in 1987 when I joined the International Rice Research Institute (IRRI) in the Philippines. We have been colleagues and close friends since then. Kei Otsuka’s research on technical change in small farm agricultural systems in Asia has had a profound impact on our understanding of the Green Revolution. Kei’s research on technology transfer from Asia to Africa has been extremely influential in African agricultural development policy. Kei is a true economist; he always reaches back into his learnings of economic theory and principles to provide explanations and solutions for real-world problems in developing countries. I am honored and delighted to be part of the Festschrift celebrating his enormous lifetime achievements.