12

 Harris has recently reviewed the methodology used in the Stanford-Cornell

type approach to the analysis of market performance and makes a similar

observation (18):

 In dealing with easily available, even if qualitatively poor, data
 on agricultural commodity prices the analysis of market performance
 has been diverted away from the consideration of interrelationships -
 between the control of commodities and money; between exchange and
 production essential for the identification of the role of the marketing
 system in economic development. In this sense not only is the
 methodology itself usually statistically and interpretatively spurious
 but also the fetishism of competition in agricultural commodity markets
 (as revealed by price and commodity analysis here) has led agricultural
 marketing economists to overnarrow at least a decade of a substantial
 part of our research.

 Another problem with much of the broader diagnostic research is the

tendency to utilize secondary and usually macro-level data in testing for

conditions of structure, conduct and performance predicted by the perfectly

competitive model. Commodity studies of market flows, margins, elasticities,

concentration, competition and policies are generally based on industry or

regional-level data which do not permit focusing on the micro-level behavior

of marketing agents, including farmers' marketing decisions in the rural

areas. These studies frequently include assumptions of homogenous behavior

on the part of farmers and marketing agents and use data that are averages

of many observations (e.g., monthly price data) and thus obscure important

variations in market behavior. Results are often inadequate for making

specific recommendations for improvements in rural and/or urban markets,

especially if the objective is to extend improved services to specific target

groups such as small-scale farmers, other low income rural residents or low

income urban consumers.

 Still another problem of much of the broader diagnostic research for

guiding overall marketing policy stems from its focus on few, if any, of

the levels of interaction in the vertical marketing channels between farmers