  Understanding consumption dynamics and its impact on the whole economy and
welfare within the present economic crisis is not an easy task. Indeed the
level of consumer demand for different goods varies with the prices, consumer
incomes and demographic factors. Furthermore crisis may trigger different
behaviors which result in distortions and amplification effects. In the present
work we propose a simple model to quantitatively describe the time evolution
over a brief period of the amount of money an average consumer decides to
spend, depending on his/her available budget. A simple hydrodynamical analog of
the model is discussed. Finally, perspectives of this work are briefly
outlined.
