 |
Navigation |
 |
|
 |
|
macro
in a nutshell
Aggregate expenditure |
|
|
Aggregate
expenditure is the sum of all planned (or voluntary) spending
on domestically produced goods and services. Actual expenditure in
the economy may differ from aggregate expenditure, because the former
also includes unplanned (or involuntary) investment spending.
-
The spending categories making up aggregate expenditure are
-
investment
I,
government
spending G,
net exports NX (the difference between exports
and imports), and
consumption C.
-
Suppose investment is independent of income at 400. Then investment
is always the same, no matter how high income is. In a graph measuring
income along the horizontal axis and investment along the vertical
axis this income-independent investment level is represented by a
horizontal line. Supposing that government spending at 500 and net
exports at 300 are independent of income too, these spending categories
may be stacked. Their sum is also a horizontal line. Finally, suppose
people consume a constant fraction of their income, say 80%. Then
consumption is zero if income is zero, and it is 800 if income is
1000. Generally, the consumption line has a positive slope smaller
than 1. Stacking consumption on top of the three income-independent
(or autonomous) spending categories gives the aggregate demand line
shown in the graph.
Further reading
on pp. 38-42. |
|
|