00:01
So here, this is fundamentally a question about macroeconomic equilibrium.
00:05
And i assume that you've seen gdp before, right? and gdp can be expressed in two ways.
00:13
So you have the expenditure approach to gdp, which you have probably seen before, right? look something like this.
00:21
Sometimes you get plus net exports added on the end.
00:25
But you can also have the income approach to gdp, which says that you get, you get, consumption plus saving, which i'll call s plus taxes, which i'll call t.
00:38
That's the income approach.
00:39
So the idea is that society buys consumption goods, investment goods, and government goods.
00:45
But from the perspective of the individual, people spend their money on consumption, or they save it, or they give it to the government back in taxes.
00:52
And in both of these cases, we have y on the left -hand side.
00:56
So if i set these equal to each other, we get this.
01:00
Very famous equation...