Engel's law is an economic relationship proposed by the statistician Ernst Engel in 1857. Even though Engel's law was proposed roughly 160 years ago, it holds relevance today in the context of poverty, especially the reduction of poverty. For instance, the lines and rates for national poverty are often determined by the food share of household expenditure. One definition of Engel's law by the Merriam-Webster dictionary is as follows: "a generalization in economics: such as family income increases, the percentage spent for food decreases, that spent for clothing, rent, heat, and light remains the same, while that spent for education, health, and recreation increases" A quotation of Engel himself from 1932 reveals the same relationship between income and percentage of income spent on food, but also indicates the application of Engel's Law in measuring standard of living: "The poorer is a family, the greater is the proportion of the total outgo [family expenditures] 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." Understanding Engel's law Engel's law states that an increase in the income of a family decreases the proportion of which the income is spent on food, even though the total amount of food expenditure is increasing. In other words, the income elasticity of demand of food is between 0 and 1. For instance, a family with a $5000 monthly income is spending $2000 on food - which is 40%. Say the income of this family would increase by 40% - to $7000. In this case they would spend around $2500 on food. So, although the absolute expenditure on food would increase by 25%, the relative proportion would decrease by 35.7%. This example clearly shows the notion supported by Engel's Law, which is that households with lower income will spend a larger amount of their income on food items than the ones in the middle- or higher-income levels. For a poor family, the budget expenditure is a big portion of their total budget, while the rich tend to spend more of their money on items such as entertainment and luxury goods. To be clear, Engel's law does not imply that food spending remains unchanged as income increases; instead, it suggests that consumers increase their expenditures for food products in percentage terms less than their increases in income.