On what basis does Keynes (General theory) discount the list of other feasible variables? In particular, does he dismiss subjective variables because he cannot measure them?

Abstract

Keynes, in his book, ?The General Theory of Employment, Interest and Money' argues that objective variables are the most useful tools that fiscal policy-makers can adopt. In this book, Keynes' primary objective is to discover the prime determinants of the volume of employment. He asserts that proceeds from employment are used in two ways: for consumption and investment. He focuses specifically on consumption and sets out a function that relates the consumption in terms of wage units to the income in terms of wage units in order to determine what factors determine the sum spent on it.