One of the lasting effects of gains in agricultural productivity in Asia and elsewhere has been a relatively steady decline in the price of food staples from the 1970s until recent times. Because of the inelastic demand for rice and wheat as well as the competitive nature of agricultural markets, there were concerns that the benefits of technology gains in agriculture would flow exclusively to consumers, adding further to the gap between agricultural and non-agricultural incomes (Quizón and Binswanger, 1986). Nevertheless, early studies suggested that this was not the case and that significant income gains accrued to rural villages following the adoption of the new varieties (Blyn, 1983; Ahluwalia, 1978; Pinstrup-Andersen and Hazell, 1985; David and Otsuka, 1994). Much of the early evidence was selective and not broadly representative of national economies, but with time, and especially after the launch of representative living standards surveys by the World Bank in the 1980s, better measures of the broad and cumulative effects on poverty of improving agricultural productivity emerged. And, on balance, there is now strong evidence that gains in agricultural productivity, especially in combination with investments in education and infrastructure, are transformational elements of poverty reduction and economic growth and that advances in agricultural techniques have contributed significantly to rising farm incomes and reductions in rural and urban poverty.<sup>8</sup> Eventually, Asia’s Green Revolution came to encompasses technological innovations in a number of crops, but breakthroughs in wheat and rice served as catalysts and conduits for most of the benefits associated with Asia’s Green Revolution.<sup>9</sup> And with the Asian experience in mind, a number of authors have called for a similarly styled African Green Revolution based smallholder agriculture, staple crops and high-input technologies designed to substantively improve agricultural productivity.<sup>10</sup> Even when successful, the approach of expanding agricultural productivity by relying on input-intensive methods is not without problems. Many relate to the poor management of natural resources, especially water and soils, and to the human and environmental costs of mismanaged chemical inputs<sup>11</sup> . Nevertheless, there is evidence that input intensive techniques can be effective in Africa, particularly in the case of rice, which we discuss below. More importantly, current less input-intensive practices appear unsustainable in Africa. This is

> 8 The literature is large, but for a sampling of the contributions of agricultural productivity on growth and poverty reductions see: Thorbecke and Jung (1996); Datt and Ravallion (1998); Foster and Rosenzwieg (2004); Mundlak, Larson and Butzer (2004); Chen and Ravallion (2004); Christiansen and Demery (2007); Gulati and Fan (2008); Bezemer and Headey (2008), Otsuka, Estudillo and Sawada (2009), and Suryahadi, Suryadarma and Sumarto (2009). There is also a large literature about the consequences of the Green Revolution for caste, gender and culture. See Samaddar and Das (2008) and references therein.

> 9 The start of the green revolution is often set at 1966 when the first modern or high-yielding varieties of rice and wheat were introduced in developing countries, although a case could be made for an earlier start with the development of new wheat varieties in Mexico. For an early discussion of the Green Revolution see Hayami (1971). Evenson and Gollin (1997) and Evenson (2004) provide later perspectives.

> 10 See, for example, Mosley (2002), Evenson (2003), Evenson and Gollin (2003), Djurfeldt et al. (2005), and Annan (2007).

> 11 See Pimentel and Pimentel (1990), Byerlee and Siddiq (1994) Huang, Hu, Rozelle and Pray (2008) and Klemick and Lichtenberg (2008), and references therein.

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