Engel's law is an economic relationship proposed by the statistician Ernst Engel in 1857.

德国经济学家：Engel coefficient。
Engel coefficient is simply a food budget share.

The Engel coefficient is used for the purpose by The United Nations (UN),
where a coefficient above 59% represents poverty,
50-59% represents a state where daily needs are barely met,
40-50% a moderately well-off standard of living,
30-40% a good standard of living
and below 30% a wealthy life.


=====我的恩格尔系数比随机误差小，所以我对通货膨胀这个问题根本不开口。

Ernst Engel (/ˈɛŋɡəl/; German: [ˈɛŋəl]; 26 March 1821 – 8 December 1896) was a German statistician and economist, famous for the Engel curve and Engel's law.