MSU Agricultural Economics  Research > Food Security III > Policy Syntheses > No. 28



Synthesis of Findings and Lessons Learned


P. Anandajayasekeram, William A. Masters, and James F. Oehmke

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Food Security II Cooperative Agreement between U.S. Agency for International Development, Global Bureau, Economic Growth Center, Office of Agriculture and Food Security and Department of Agricultural Economics, Michigan State University

BACKGROUND: Since 1992, a series of studies identifying and quantifying the impacts of technology development and transfer (TDT) for agricultural and natural resources in sub-Saharan Africa has been funded by AID and other donors. These studies have played a crucial role in reversing the conventional wisdom of the 1980s and early 1990s, namely that TDT hadn't generated impact. In fact, African agricultural TDT has contributed to substantial improvements in the welfare of African producers and consumers. Moreover, the studies have helped to delineate the role that agricultural TDT can play in helping to address the very serious challenges that confront Africa and Africans today.

This document synthesizes the current state of knowledge about the impacts of African agricultural TDT. It is based on results presented at the Roundtable Discussion on Impact Assessment of African Agricultural Technology Development and Transfer, held in Washington D.C., Jan. 9-10, 1997.


Evidence: Although countries' individual experiences are complex and uneven, examination of African aggregate data shows evidence of significant deterioration between 1971 and 1984, followed by a modest recovery over the past 12 years. The FAO index of total agricultural production fell consistently from 1971 to 1984, for a cumulative decline of 22%. Coupled with rapid population growth, this led a decline of 40% in agricultural exports and a tripling of imports. From 1984 to 1995 there is a sustained improvement in yields in East, West and Southern Africa. In the Sahel, cereal grain production doubled between 1984 and 1995. For all of sub-Saharan Africa, agricultural production has kept pace with population growth over the last 12 years.

A number of factors--policy reform, improved rainfall in some regions, reduced population growth in some areas, and relative political stability, among others--have contributed to the shift from a declining agricultural to one of modest growth. The aggregate evidence on Africa's success in increasing average cereal yields also points to an unrecognized story of successful TDT, as farmers adopt increasingly productive varieties and production techniques.

Evidence from case studies is summarized by the rate of return (ROR) on investment in TDT. The ROR is the single most convenient and accurate number for summarizing the benefits, costs and time pattern of TDT activities. The benefits included are usually directly related to producer and consumer well-being. The ROR studies are categorized as ex post, those which quantify historical benefits and costs (Table 1; for earlier studies see Policy Synthesis No. 20), or ex ante, which project future benefits and costs (Table 2).

The evidence from the impact case studies indicates that agricultural and natural resource TDT activities have generated impact sufficient to justify the investments. Impacts have been generated across commodities and countries, in different agroclimatic settings. The evidence is sufficient to support continued funding of agricultural and natural resource TDT in Africa.

Methodological Issues: The ROR may well be the best single-number summary available of TDT impact, but it is still only a single indicator. This leads to three methodological issues that impact assessments should address. First, the current trend of expanding the range of benefits quantified, for example by including environmental benefits (and costs), is appropriate and should be continued. Second, the comprehensiveness of benefits included needs to be more clearly communicated to policy makers. For example, the standard calculation of consumer benefits implicitly includes better nutrition, even if this benefit is not measured explicitly and hidden in the economic calculations. Third, efforts to understand the attribution of benefits among TDT and complementary investments should be continued. The purpose of these efforts is not to define which activity should get a bigger share of the budget, but to design a portfolio of complementary investments that generates the greatest possible impact. Similarly, impact assessments that investigate constraints to generating impact may help target funds toward those areas that have the greatest potential payoffs.

Thematic and Programmatic Issues: The impact case studies identify several issues that will have significant affects on the future impacts of TDT:

To give one example, the ROR evidence indicates that breeding activities in low rainfall areas have generated modest RORs; innovative natural resource management techniques may have higher payoffs, and may improve the impact of breeding.

THE FUTURE OF IMPACT ASSESSMENT: Impact assessment studies serve several purposes. They can (and have) help to generate additional funds; they provide information that is used and is useful in determining TDT priorities; they provide recognition to and by scientists of social welfare improvements; and they help policy makers to think about the real benefits of agriculture and agricultural TDT. For these reasons, impact assessment is being, and should continue to be, institutionalized in national and regional research organizations. Future impact assessments can improve by better communicating results, providing information on critical areas of needed TDT, and by defining those characteristics of the enabling environments that will help scientists to generate the greatest improvements in social well-being.

*Partial funding for this research was provided by the Technology Development and Transfer Unit of the Productive Sector Growth and Environment Division, Office of Sustainable Development, Bureau for Africa, USAID (AFR/SD/PSGE/TDT). The synthesis was prepared under the Food Security II Cooperative Agreement Between AID/Global Bureau, Office of Agriculture and Food Security, and the Department of Agricultural Economics at Michigan State University. The views expressed in this document are exclusively those of the authors.

Anandajayasekeram is Economic Impact Advisor, SACCAR; Masters is assistant professor, Purdue Uniersity; and Oehmke is associate professor, MSU.

Table 1. Summary of Recent Impact Assessments of African Agricultural Technology with Ex-Post Rates of Return.

Ewell, 1992 East Africa, potato, 1978-1991 91% Regional network/NARS collaboration.
Sanders, 1994 Ghana, maize, 1968-1992

Cameroon, sorghum, 1980-1992



New cultivars with additional inorganic fertilizer.

One new cultivar (S-35).

Smale and Heisey, 1994 Malawi, maize, 1957-1992 4-7% Improved research performance since 1985.
Kupfuma, 1994 Zimbabwe, maize, 1932-1940 43.5% Research and extension activities of the Department of Research and Specialist Services.
Khatri, Thirtle and van Zyl, 1995 South Africa, aggregate agriculture 44% Econometric decomposition of agricultural productivity growth.
Ahmed, Masters and Sanders, 1995 Sudan, sorghum, 1979-1992 53-97% New cultivar (HD-1) introduced in irrigation scheme, with additional inorganic fertilizer and erosion control.
Seck, Sidibé, and Béye, 1995 Senegal, cotton, 1985-1993 34-37% New cultivars; moderate to high levels of inorganic fertilizers were already in use.
Ouedraogo, Illy and Lompo, 1996 Burkina Faso, maize, 1982-1993 78% Varietal improvement.
Ouedraogo and Illy, 1996 Burkina Faso, stone dikes, 1988-1994 7% Natural resource management/soil and water conservation technique.
Seidi, 1996 Guinea Bissau, rice, 1980-1994 26% New cultivars for mangrove-swamp areas.
Makanda and Oehmke, 1996 Kenya, wheat, 1921-1990 0-12% Based on econometric estimation of research impact on average yield.
Akgnungor et al., 1996 Kenya, wheat, 1921-1990 14-30% Time-series econometric methods. National data show more rapid yield growth following independence.

Table 2. Summary of Impact Studies of African Agricultural Technology with Ex-Ante ROR or Benefit-Cost Ratio Results




Norgaard, 1988 Africa, 1977-2003, cassava 149:1 Benefit: Cost ratio, attributes much of the value of cassava production to mealybug control.
Schwartz et al., 1989 Senegal, 1981-2005, cowpea 63% TDT impacts consist of improved household food security and scientist training.
MacMillan et al., 1991 Zimbabwe, 1991-1996, maize 1.35:1 Benefit-cost ratio for outreach and demonstration of improved varieties for smallholders. Implied ROR of 22%.
Laker-Ojok, 1994 Uganda, 1985-2996: maize






Sterns and Bernsten, 1994 Cameroon, 1979-98: cowpea




Cowpea TDT introduced a new farming systems; sorghum TDT added a drought-escape variety useful about one year in three.
Mazzucato and Ly, 1994 Niger, 1975-2011, combined millet, sorghum and cowpea 2-10% Low RORs attributable to few varietal releases (3 millet and 1 cowpea) and low adoption of released varieties.
Bertelsen and Ouédraoga, undated Burkina Faso, 1990-2003, zaï 53% Zaï is an indigenous knowledge technique of incorporating organic fertilizer in sorghum and millet planting holes before introducing the seed.
Fisher, Fall and Sidibé, 1995 Senegal, 1995-2004, rice 66-83% New cultivars and inorganic fertilizer.
Tre, 1995 Sierra Leone, 1976-2010, rice 18-21% New cultivars for mangrove swamps.
Anandajayasekeramet al., 1996 Zimbabwe, 1980-99, sorghum

Namibia, 1988-99, millet



New cultivar (SV-2).

New cultivar (Okashana 1).

Kuyvenhoven, Becht and Ruben, 1996 Mali, rock phosphate 43-


Assumes 50% of production value due to phosphate.
Aghib and Lownberg-DeBoer, undated Ten countries, 1985-2009, sorghum 58% Evaluates 8 INTSORMIL striga-resistant varieties in ten countries. Includes WVI extension and their costs.