Bunch Maps

Abstract

Bunch maps were developed by Ragnar Frisch (1934) to deal with the problems of confluence analysis. By ‘confluence analysis’ he meant the study of several variables in some sets of which a regression equation might have a meaning, while in others it might not because of the existence of more than one relation between the variables. Frisch’s exposition of bunch maps was based on a situation where each variable in a set could be split into two components: one, the systematic component, was connected with the other variables; the other, the disturbance, was not so connected. The method was used to try to determine sets of variables in which one, and only one, exact linear relation held between the systematic components of the variables. Examples of the use of the method were given for constructed data where exact relations did exist. It is less clear whether they were assumed to exist in examples of applications to actual economic data. The other major applications of bunch maps were in Richard Stone’s work on consumers’ expenditure (Stone, 1945, 1954), but he did not consider an assumption of exact linear relations between systematic components as satisfactory.