Key References

Significant publications of ex post impact assessments (epIAs), both commissioned by SPIA and CGIAR Centers and CRPs showcasing a range of methodological approaches and impacts. SPIA is developing a quality rating system for epIAs and eventually, some of the high quality epIAs will be showcased here.

Click here for a full list of CGIAR epIAs or choose a publications category in menu bar above

Adoption of Modern Varieties of Food Crops in Sub-Saharan Africa

Adoption of Modern Varieties of Food Crops in Sub-Saharan Africa

ISPC, SPIA, 2014

In the late 1990s, a global initiative on the impact assessment of crop varietal change estimated that modern varieties (MVs) accounted for about 22% of the growing area of primary food crops across Sub-Saharan Africa (SSA) (Evenson and Gollin, 2003). This baseline has recently been updated, widened, and deepened in the CGIAR’s project Diffusion and Impact of Improved Crop Varieties in Sub-Saharan Africa (DIIVA), supported by the Bill and Melinda Gates Foundation. Seven CGIAR Centers and more than 200 individuals – mainly crop improvement scientists in national programs – participated in the DIIVA project, which was directed and coordinated by the Standing Panel on Impact Assessment (SPIA) of the CGIAR and administrated through Bioversity International.

PDF icon SPIA_Impact-Brief-42_July2014.pdf
Cite as:

ISPC, SPIA 2014. Adoption of modern varieties of food crops in Sub-Saharan Africa. Impact Brief No. 42.

Enhancing ex post impact assessment of agricultural research: the CGIAR experience

Enhancing ex post impact assessment of agricultural research: the CGIAR experience

Kelley, T., Ryan, J. & Gregersen, H., 2008

An overview of the rationale for SPIA and how ex-post impact assessment in the CGIAR system works in the journal Research Evaluation.

Enhancing ex post impact assessment of agricultural research: the CGIAR experience
Cite as:

Kelley, T., Ryan, J. & Gregersen, H. 2008. Enhancing ex post impact assessment of agricultural research: the CGIAR experience. Research Evaluation 17(3): 201–212

Recent advances in impact analysis methods for ex-post impact assessments of agricultural technology: options for the CGIAR

Recent advances in impact analysis methods for ex-post impact assessments of agricultural technology: options for the CGIAR

De Janvry, A., Dustan, A. & Sadoulet, E., 2011

This paper was commissioned by SPIA in 2010 and appraises a range of recent methodological innovations that are now available to practitioners when carrying out analysis of the impact of agricultural research. It argues for greater focus on methods that provide rigorous casual reference.

Recent advances in impact analysis methods for ex-post impact assessments of agricultural technology: options for the CGIAR
Cite as:

De Janvry, A., Dustan, A. & Sadoulet, E. 2011. Recent advances in impact analysis methods for ex-post impact assessments of agricultural technology: options for the CGIAR. Rome, ISPC. 40 pp.

Impact assessment of policy-oriented research in the CGIAR: evidence and insights from case studies

Impact assessment of policy-oriented research in the CGIAR: evidence and insights from case studies

CGIAR, SPIA, 2008

Policy-oriented Research (POR) is research that aims to influence the decisions made by governments or other institutions that are embodied in laws, regulations, or activities that affect people’s lives and livelihoods. POR has recently accounted for an increasing share of research expenditures in the CGIAR, rising from 9 percent in 1995 to about 18 percent currently. Yet it is a theme where evidence of impacts is scant.

The Science Council’s study of POR was conducted at the request of several members of the CGIAR. This is a collection of seven case studies, selected from a competitive call of 14 submissions. Five of the seven case studies were able to measure the economic impacts of the policy changes associates with the POR and the returns on the POR investments themselves, although none was able to translate these impacts into quantified effects of poverty reduction or food security. In this respect, these impact assessments are not so different from most others undertaken in the CGIAR.

Adding together the estimates economic impacts of POR from the five relevant case studies gives us a cumulative NPV of about US$ 750 million. If we add this amount to the US$200 million in benefits estimated for three cases cited in the scoping study report, we arrive at a current estimate of US$950 million as NPV of documented benefits from POR in the CGIAR system. These benefits stand in comparison with US$800 million of cumulative investment in POR in the CGIAR up to 2004, a figure which has probably surpassed US$900 million in 2008. However, if donors are to be convinced that the CGIAR’s increasing emphasis on POR over the past 20 years is justified, further PORIA studies are needed to provide a more comprehensive estimate of the benefits of POR across the entire CGIAR system.

Download impact brief
Download full report
Cite as:

CGIAR Science Council. 2008. Impact assessment of Policy-Oriented Research in the CGIAR: evidence and insights from case studies. A study commissioned by the Science Council's Standing Panel on Impact Assessment, CGIAR Science Council Secretariat: Rome, Italy. 99 pp.
CGIAR Science Council. 2006. Impact assessment of policy-oriented research in the CGIAR: a scoping study report. A study commissioned by the Science Council's Standing Panel on Impact Assessment, CGIAR Science Council Secretariat: Rome, Italy. 39 pp.
CGIAR, SPIA. 2008. Policy-oriented Research in the CGIAR: assessing the impact. Science Council Brief No. 23

Publication cover image thumbnail

The economic and poverty impacts of maize research in West and Central Africa

The economic and poverty impacts of maize research in West and Central Africa

Alenea, A. D. et al., 2009

This article assembles the results of three multicountry surveys on variety performance and adoption patterns to measure the impacts of maize research in West and Central Africa from 1981 to 2005, and uses cost data since 1971 to compute social rates of return on public investments in maize research in the region. Adoption of modern varieties increased from less than 5% of the maize area in the 1970s to about 60% in 2005, yielding an aggregate rate of return on research and development (R&D) investment of 43%. The estimated number of people moved out of poverty through adoption of new maize varieties rose gradually in the 1980s to more than one million people per year since the mid 1990s. Over half of these impacts can be attributed to international maize research at IITA and CIMMYT. The article concludes with a discussion of strategic options to enhance the impacts of maize research in the region.

Download impact brief
The economic and poverty impacts of maize research in West and Central Africa
Cite as:

Alenea, A. D. et al. 2009. The economic and poverty impacts of maize research in West and Central Africa. Agricultural Economics 40: 535–550


ISPC, SPIA. 2010. Improved maize benefits millions of Africa's poor. Impact Brief No. 34

Natural resources management research impacts: evidence from the CGIAR

Natural resources management research impacts: evidence from the CGIAR

CGIAR, SPIA, 2006

This document presents the results of SPIA’s initiative to assess the impact of past investments in NRMR in the CG system. NRMR encompasses research on land, water and biodiversity resources management. It focuses on generating knowledge that results in technology options and how to sustainably enhance the productivity and stability of ecosystem resources. The initiative was a response to concerns on the dearth of documented credible evidence that NRMR substantially contributed to realizing the CGIAR mission on poverty, food security, and the environment.

Seven case studies are the main focus of the SPIA NRMR impact assessment initiative. They cover a range of Centers, geographical regions, and both macro- and micro-oriented research projects. While the results from these case studies suggest returns on NRMR are lower than returns from CGI, meaningful cross-comparison is not possible. Seven cases of NRMR impacts are unequal comparators for hundreds of CGI studies. More comprehensive assessments of the impact of NRMR are needed.

Download full report
Cite as:

CGIAR, SPIA. 2006. Natural resources management research impacts: evidence from the CGIAR. Rome, Science Council Secretariat. 64 pp.

CGIAR and NARS partner research in sub-Saharan Africa: evidence of impact to date

CGIAR and NARS partner research in sub-Saharan Africa: evidence of impact to date

Maredia, M.K., and D.A. Raitzer, 2006

Over its lifetime, the Consultative Group on International Agricultural Research (CGIAR) has invested 40% of its resources on research and capacity strengthening of agriculture in sub-Saharan Africa (SSA). While there are differing impressions of the impact of this investment on the livelihoods, health and prosperity of Africans, there has been no consensus on the issue, nor has a systematic, analytical attempt been made to obtain a clearer picture of the overall impact of the CGIAR in the region. This is a more quantitative assessment of the impact of CGIAR investment in SSA as a follow-up to an earlier desk study of available evidence of such impacts (Gryseels and Groenewold, 2001).

This analysis attempts to identify, assess, and synthesize available evidence on the impact of agricultural research, so as to offer a systematic answer to the question: “Have the investments made by CGIAR–NARS in SSA been justified by documented benefits to date?”. Impact Brief No. 9 for this study is titled "Costs and Benefits of CGIAR–NARS Research in Sub-Saharan Africa" and is available on the site.

Download full report
CGIAR and NARS partner research in sub-Saharan Africa: evidence of impact to date
Cite as:

Maredia, M.M. & Raitzer, D.A. 2006. CGIAR and NARS partner research in sub-Saharan Africa: evidence of impact to date. Rome, Science Council Secretariat. 78 pp.

Publication cover image thumbnail

More trees, more milk, more money

More trees, more milk, more money

ISPC, SPIA, 2010

The objective of this study is twofold, to demonstrate (1) the effects of fodder shrubs on milk production and their value at the household and regional level and (2) the contribution of research by the World Agroforestry Center towards strengthening the impact of fodder shrubs. The study is a synthesis of previous studies related to dissemination, adoption and impact combined with two new analyses, one quantitatively measuring the impact of the shrubs through econometric analysis and the other a qualitative analysis to better understand constraints on adoption and gender issues related to participation and control of benefits from fodder shrubs.

Among the study findings are that fodder shrubs have been widely adopted in East Africa, by an estimated 205,000 smallholder dairy farmers by 2005. Women were active in plating shrubs, as monitoring found almost half of planters to be women. Several studies have confirmed that shrubs do have an impact on milk production. While feeding trials have found that 1 kilogram of calliandra increases milk production by 0.6-0.8 kilograms, a new survey of farmers’ perceptions in Kenya found the effect to be about half as large after controlling for the effects of breeds, season and other feeds. Whether the effect is the lower or higher estimate, the overall impact of the shrubs in terms of additional net income from milk is high, at US$19.7 million to US$29.6 milion in Kenya alone over the past 15 years.

Download impact brief
More trees, more milk, more money
Cite as:

ISPC, SPIA. 2010. More trees, more milk, more money. Impact Brief No. 35

Publication cover image thumbnail

The impacts of CGIAR research: a review of recent evidence.

The impacts of CGIAR research: a review of recent evidence.

Renkow, M. & Byerlee, D., 2010

We review evidence on the impacts of CGIAR research published since 2000 in order to provide insights into how successful the CGIAR Centers have been in pursuing the System’s core missions. Our review suggests that the CGIAR research contributions in crop genetic improvement, pest management, natural resources management, and policy research have, in the aggregate, yielded strongly positive impacts relative to investment, and appear likely to continue doing so.

Crop genetic improvement stands out as having had the most profound documented positive impacts. Substantial evidence exists that other research areas within the CGIAR have had large beneficial impacts although often locally and nationally rather than internationally. However, the “right-time, right-place” nature of successful policy research and the relatively limited geographic scale of much natural resource management research often limits the overall scale of impacts of these programmatic thrusts vis-à-vis genetic improvement research.

We conclude that given the evidence available, the CGIAR’s portfolio of research allocations has become overly skewed toward natural resource management and policy research over time. Hence, restoring somewhat the share of resources allocated to crop genetic improvement is warranted. In addition, the CGIAR needs to prioritize impact assessment of resource management and policy research to deepen its understanding of the social and environmental impacts of its work.

Download full report
Cite as:

Renkow, M. & Byerlee, D. 2010. The impacts of CGIAR research: a review of recent evidence. Food Policy 35: 391–402.

One million hectares of CIP potatoes

One million hectares of CIP potatoes

ISPC, SPIA, 2010

This is a study of the contribution of the International Potato Center (CIP) research on varietal change and potato production, particularly in developing countries. More specifically, the study focuses on adoption of CIP-related varieties in those countries.

Among the study findings:

  • By 2007, breeding programs in 23 surveyed developing countries had released 681 new varieties, 251 of which had their origins in CIP germplasm.
  • In Ethiopia, Kenya, Rwanda, Tanzania, and Uganda, the aggregate area under CIP-related varieties increased by more than 230,000 hectares between 1997 and 2007, equivalent to one third of the worldwide increase.
  • CIP-related varieties are now planted on more than 100,000 hectares in Peru.
  • In Asia, 10% of the potato-growing area was planted with CIP-related varieties by 2007, up from 3.5% in 1997.
Download impact brief
One million hectares of CIP potatoes
Cite as:

ISPC, SPIA. 2010. One million hectares of CIP potatoes. Impact Brief No. 36


Thiele, G. et al. 2008. Varietal change in potatoes in developing countries and the contribution of the International Potato Center: 1972-2007. Lima, CIP. Working Paper No. 6, 46 pp.

Publication cover image thumbnail

Crop variety improvement and its effect on productivity: the impact of international agricultural research

Crop variety improvement and its effect on productivity: the impact of international agricultural research

Evenson, R.E. & Gollin, D., 2003

This book represents the most comprehensive effort to date to document adoption and impacts of genetic improvement in the mandate crops of the CGIAR. CABI International, the publisher, has kindly given permission for us to post the full text of this book as a PDF. Please note that this is intended only for personal use and should not be posted to any other website.

Also see Diffusion and Impact of Improved Varieties in Africa (DIIVA) page, an initiative that aims to update these studies and related publication here .

Crop variety improvement and its effect on productivity: the impact of international agricultural research
Cite as:

Evenson, R.E. & Gollin, D. 2003. Crop variety improvement and its effect on productivity: the impact of international agricultural research. Wallingford (UK), Cabi publishing. 522 pp.

Publication cover image thumbnail

The impact of modern rice varieties on livelihoods in Bangladesh

The impact of modern rice varieties on livelihoods in Bangladesh

CGIAR, SPIA, 2006

This case study builds on an ongoing large-scale quantitative research project undertaken by BIDS/IRRI since 1987 originally in 64 unions from 57 districts of the country. It adds a qualitative research component to examine the impact of modern rice varieties (MVs) on livelihoods in a structured sample of eight of these villages across a range of favorable and unfavorable contexts. This component was structured using the sustainable livelihoods framework and employed focus groups stratified by poverty ranking and gender.

Results showed that the adoption of MVs had significant positive impacts on crop yields and farm incomes for households with access to land. However, as rice farming accounted for only 20 per cent of total household incomes in 2001, the overall impact on incomes was relatively small. Although the profitability of rice is declining due to falling prices, higher input costs and reduced farm sizes, the crop nevertheless contributes greatly to food security and acts as an entry point to off-farm employment.

Download impact brief
The impact of modern rice varieties on livelihoods in Bangladesh
Cite as:

CGIAR, SPIA. 2006. The impact of modern rice varieties on livelihoods in Bangladesh. Science Council Brief No. 8


Hossain, M., Lewis, D., Bose, M.L. & Chowdhury, A. 2003. Rice research, technological progress, and impacts on the poor: the Bangladesh case (Summary report). Washington, D.C, IFPRI. EPTD Discussion Paper No. 110. 65 pp.

Publication cover image thumbnail

When zero means plenty: the impact of zero-tillage in India

When zero means plenty: the impact of zero-tillage in India

CGIAR, SPIA, 2006

The most widely adopted resource-conserving technology in the Indo-Gangetic Plains (IGP), particularly in India, is Zero-tillage (ZT). CIMMYT's role with regard to ZT in India was to make the diffusion process faster and more efficient. CIMMYT facilitated technology introduction by helping with the design experiments for technology testing and local adaptation. Using conservative benefit estimates the program yielded a net present value (NPV) of US$94 million; equivalent to a benefit-cost ratio (BCR) of 39 and an IRR of 57%. The economic surplus primarily benefited consumers, at 65%, compared to producers, at 35%.

Also see the publication Natural Resources Management Research Impacts: Evidence from the CGIAR (SPIA 2003) for the CIMMYT case study – Assessing the Impact of Zero Tillage in India’s Rice-wheat Systems.

Download impact brief
When zero means plenty: the impact of zero-tillage in India
Cite as:

CGIAR, SPIA. 2006. When zero means plenty: the impact of zero-tillage in India. Science Council Brief No. 13


CGIAR, SPIA. 2006. Natural resources management research impacts: evidence from the CGIAR. Rome, Science Council Secretariat. 64 pp.