After having discussed the wage forms over the centuries, let's have a look at today, in a troubled social context ("food riots" part-time work, high unemployment rate), at the forms of sustenance of the individual, through the ages. Let's discuss the issues of purchasing power, consumption and income. Since Antiquity, it becomes apparent that the salary of the worker is not enough nor for his sustenance, and, a fortiori causa, neither for the maintenance of a family. With the end of the Black Death, resulting in a significant demographic decline, wage negotiation become easier. Paradoxically, archival sources show that the poverty of wage income is sometimes coupled with a rise in the standard of living. What does that mean ? What are the real income of the worker?