The paper considers a simple aggregated consumption function for Russian economy in which households consume a constant fraction of a permanent income. The value of this fraction is estimated by households within the framework of the adaptive expectations process based on the dynamics of GDP at constant consumption prices. Testing for a structural break at an unknown date in the parameter of the propensity to consume is performed. The results of econometric estimation, taking into account the presence of an endogeneity in the regression equation, demonstrate that after 2014 there was a structural break, as a result of which the parameter of the propensity to consume of permanent GDP decreased by 6.5—9.2%.