Explain Engel's law of consumption with an example.

1. 1 · Open with the source. Ernst Engel, a German statistician, studied the budgets of Belgian working-class families and published his law in 1857.
2. 2 · State the law. As family income increases, the percentage of income spent on food decreases, though the amount spent may rise.
3. 3 · List the observations.
   • Food: share decreases.
   • Clothing: share remains about the same.
   • Rent, fuel and light: share remains about the same.
   • Education, health and recreation: share increases.
4. 4 · Illustrate. [Table: three families with income, food spending and food share of 50%, 35% and 20%]
5. 5 · Significance. The food share (Engel ratio) is an index of the standard of living: the lower it is, the better off the family.
6. 6 · Nutrition link. Families with a high food share need help getting more nutrients per rupee.
7. 7 · Close in one line. Engel's law shows how spending shifts from necessities to comforts as income grows.

Scoring tip: State the law in one exact sentence first, then the small table. Make sure your example's percentages are worked out correctly.