This chapter reflects on the impact of private agricultural research in less developed nations, on the policies that affect that research and on some tools available to social scientists for improved evaluation of that research. While private agricultural research has historically been very small compared to its publicly funded counterpart, it is by no means insignificant and research very clearly shows its importance at national and regional levels. In fact, globally private research has now outstripped public research, although that trend lags substantially in less developed nations (Fuglie et al., 2011). Moreover, there are striking differences in policy support across time and across nations (or even within nations). This chapter reviews recent literature on research output and intellectual property rights (IPR) protection by region, by industrial origin and by crop type. While innovation is important in its own right, the diffusion of agricultural innovations among farmers is an often overlooked but critical aspect of the innovation system. The conclusion summarizes the economic and policy determinants affecting the incentives for private agricultural research and offers some policy suggestions to encourage further investment.