Ernst Engel quotes

The poorer is a family, the greater is the proportion of the total outgo which must be used for food... The proportion of the outgo used for food, other things being equal, is the best measure of the material standard of living of a population. (Ernst Engel)
With rising incomes, the share of expenditures for food products declines. The resulting shift in expenditures affects demand patterns and employment structures. View quote
Ernst Engel