Determining the Level of personal consumption expenditures is the general idea of this paper. Traditionally, we do that by testing the effects of some factors on the level of personal consumption expenditures, and it seems to be like just a list of determinants! In fact, the main focus of this paper is not just investigating about the relation between some factors and the levels of personal consumption expenditures. However, it is to find the change of this relation conditional on an economic structural change. We will do that using empirical data of the USA economy from 1960 - 2013. This paper has two main parts; the first part has basic literature concepts about the consumption, consumer behavior, and factors affect consumption. The second part has the empirical work including all information about the data, regression model, type of tests, and results' analysis