作者：Quora用户 来源：Quora 2017-11-13 00:45
获得4.3k好评的答案@ Balaji Viswanathan：
Law of Supply & Demand:
This is the founding block of economics.
Whenever supply of something increases its price decreases and whenever supply decreases price increases.
Thus, when you have excess production of corn, food prices decrease and vice versa
You will find its applications in 1000s of places.
The growth of an economy is commonly measured in terms of GDP growth rate.
Since GDP is a measure of national income, this growth rate is a rough proxy for how an average person's income grows every year.
You already know that the price of most products now are higher than in your grandfather's time.
Inflation (measured in percent) is measure of how much a bunch of products have increased in price from last year.
In mature economies, annual inflation is around 2% - that means on an average the prices of stuff goes up by 2% every year.
The fundamental role of central banks is to manage this rate and keep it to a low positive number