The “minimized” model has income and preference constraints and no bequests. The implications in a stagnant economy defined by a lack of economic growth or population growth result in an unchanged savings rate. However, in a steadily growing economy, the national saving rate is consistent with life cycle behavior and a higher aggregate saving rate in the long run. The article carefully distinguishes between the causes of the increase or positive saving rate, using the Neisser and Bentzel effects, growth due to population growth and productivity respectively. Friedman found that productivity growth should decrease the saving rate because an increase in permanent income would increase consumption compared to an increase in income that reduces the saving rate. However, Modigliani found that if consumers planned without any anticipation of future consumption, then wages and savings based on productivity growth would be the same. For example, in the United States during the 1960s the savings rate was mainly low due to low productivity and low population growth rates. An amalgamated or less simplified model adds variables to the mix that influence saving, for example, a change in family size over the life cycle, bequests and labor supply (based on elasticity). The beauty of this model seems to be that its results are true regardless of what variables are entered