Food Production: Problems and Prospects 1 1 



experience, and to a lesser extent in Israel."^ This trend toward 

 reduced contribution of conventional inputs to total product is 

 also evident, though less pronounced, in Japan, Korea, and the 

 Philippines. 



The concept of productivity as utilized in the studies reported 

 in table 1.2 has a certain ambiguity in the light of a number of 

 "growth accounting" studies. The studies of Griliches (1962), 

 Griliches and Jorgenson (1966), and Denison (1962), in particular, 

 have shown that the typical measured productivity series con- 

 tains systematic errors. The most important errors identified by 

 these authors are associated with factor qualities. The failure to 

 measure labor services in constant skill units, for example, means 

 that changes in labor skills will form a component of measured 

 productivity change. 



Productivity growth can thus be "explained," or accounted for, 

 if data are available to actually measure changes in labor skills or 

 other types of factor quality. In addition, productivity measures 

 can reflect changes in firm organization, such as changes in firm 

 size under conditions of scale economies. They can also reflect 

 improper factor weighting. 



In the section to follow, several studies of the contribution of 

 research to productivity are reviewed. In these studies, as well as 

 in those which are reported in later chapters, a full explanation of 

 productivity change is not attained. It is not possible to obtain 

 data in sufficient detail to identify all of the components of pro- 

 ductivity. Instead, statistical models designed to identify those 

 components directly and systematically related to research (and 

 related activities) are utilized. 



Research Contribution — A Review of Past Estimates 



The increased productivity of agriculture is due to improved tech- 

 nologies and inputs. Many of the new techniques of production 

 were created by agricultural research. The pioneering work in 

 estimating the contribution of research to farm productivity is 



4. In the United States there was even a reduction in total factor inputs in the 

 period of 1950-60, but this trend was reversed in the last decade. 



