This number is called the Gross Domestic Product, or GDP, and it was invented by the economist Simon Kuznets in the 1930s, to try and gauge the size of an economy in a single, easy to understand number.

这个数字被称为国内生产总值， 或 GDP，它是由经济学家西蒙库兹涅茨在 1930 年代发明的， 目的是试图用一个简单易懂的数字来衡量一个经济体的规模。