growth, depending on the country and time period (Pingali and Heisey, 2001). Decomposition of recent measurements of African agricultural growth suggests that up to one-third of the growth in aggregate agricultural productivity is at­tributable to past investments in agricultural research (Oe-hmke et al., 1997). This roughly corresponds to a contribu­tion of agricultural research to economic growth of Va of a percentage point.
         A study on agriculture growth and productivity in the United States demonstrated similar results (Shane et al., 1998). During 1974-1991 annual growth rate of agricul­ture productivity was estimated to be 2.2% and entire econ­omy productivity growth was 0.2% in the U.S. total factor productivity (TFP) growth rate was 2.3% during 1959-91. During 1949-91, productivity growth in agriculture can be attributed to four major factors: public investment in agri­cultural R&D (50%), public expenditure on infrastructure (25%), private investment in R&D, and technological ad­vances embodied in material inputs such as fertilizers and chemicals (combined 25%).
         Technological  advancements  depend  on  the  quality and quantity of scientific capacity of the national institutes (Mashelkar, 2005). There is a positive relationship between science enrolment and technology achievement indices in­dicating that increased investment in human capacity can result in better technological advancement. This relation­ship has not been fully understood or analyzed in the devel­opment literature. In general, there is a lack of analysis or questioning of the role of increased capacity in explaining growth performance in developing counties (Ul Haque and Khan, 1997).
           Detailed evidence on the ROR of investments in agricul­tural education is very limited, but a number of studies have showed that education has a positive impact on economic growth and positive benefits to health and other noneco-nomic benefits (UNESCO and OECD 2003; Evenson, 2004; World Bank, 2007). Economic growth increases 4% for ev­ery additional year of schooling of the adult population; particularly high attainment levels in secondary and ter­tiary education are relatively more important for economic growth (UNESCO/OECD 2003). The available evidence on the impacts of tertiary education on economic growth and poverty reduction in the case of SSA Africa show that an in­crease of one year of tertiary education will result in growth increase of 6% in the first year, and about 3 % after five years (Bloom et al., 2007). Another study found that an increase in the number of degrees awarded in natural sciences and engineering in East Asia have a strong positive relationship on GDP per capital levels (Yusuf and Nabeshima, 2007). The expected rates of return to investments in education at primary, secondary and higher level for selected countries in Africa range from 24% for primary education, 18.2% for secondary to 11.4% for higher education (Psacharopoulos, 1994).
        Per capita income levels are higher among counties that have invested in educating their population (Babu and Sengupta, 2006) and increased capacity will result in better implementation of programs and policies that reduce pov­erty and hunger (Kaufman et al., 2003). Whereas there is a positive relationship between increased capacity and better governance, there is a need for better understanding of the

nature and magnitude of the capacity needed to increase governance  of development programs  and policies that translate the development goals into development outcomes (Babu and Sengupta, 2006).
          There is ample evidence available from the literature that AKST investments have contributed significantly to organizational and institutional innovations in the form of methods, tools development, capacity strengthening, and understanding how institutes interact with each other in achieving developmental goals. However, not much work has been done on assessing the RORs on investments in ag­ricultural training and capacity strengthening. Assessing the economic impacts of non-research products such as training, networking and advisory services policy and institutional re­forms need greater emphasis. Detailed analysis of causality of agricultural education and capacity strengthening on de­velopment outcomes will require identifying indicators that reflect institutional and human capacity to contribute better development processes.

8.2.4.5 Rates of return to CGIAR investments The CGIAR Science Council's Standing Panel on Impact Assessment (SPIA) commissioned an independent study to weigh the measurable benefits of CGIAR research against the total cost of system operation to 2001 (Raitzer, 2003). The analysis found that the value of documented benefits generated by the CGIAR surpasses total investment in the system. The analysts did not calculate a single benefit-cost ratio for all potential audiences. Instead, they offered five different versions of the benefit-cost ratio to allow for its sensitivity to different assumptions regarding the credibility of the values derived for key measures of benefit. The most restrictive assessment yields a benefit cost ratio of 1.9, i.e., returns of nearly 2 dollars for every dollar invested. The most inclusive estimate puts the benefits-cost ratio nearly nine times higher.
          The analysis excluded the benefits from the vast majority of CGIAR work, which has not been subject to large-scale ex-post economic assessment. The analysis aggregated only published large-scale economic assessments that met a strict set of criteria for plausibility and demonstration of causal­ity. As a result, only a few isolated examples of success are used to produce these substantial benefit levels, and many probable impacts that lack reliable quantification are omit­ted. To underscore this point, the economic value of ben­efits derived from just three CGIAR innovations is estimated to be greater than the entire US$7 billion (in 1990 prices) invested in the IARCs since the CGIAR was established. Under very conservative assumptions, benefits generated (through 2001) from (1) new, higher yielding rice varieties in Latin America, Asia, and West Africa; (2) higher-yielding wheat in West Asia, North Africa, South Asia, and Latin America; and (3) cassava mealybug biocontrol throughout the African continent combined almost twice the aggregate cumulative CGIAR costs. If slightly more generous assump­tions were applied, the estimated benefits generated to date by these three technologies rise to more than eight times the total funds invested in CGIAR research and capacity-building programs. If impact assessment were applied to a larger proportion of the system's portfolio then these three innovations will result in much higher aggregate benefit