On the 45-degree line diagram, for points that lie above the 45-degree line,
A) planned aggregate expenditure is greater than GDP.
B) planned aggregate expenditure is less than GDP.
C) planned aggregate expenditure is equal to GDP.
D) planned aggregate expenditure is less than aggregate income.
You explain to your friend Haslina, who runs a catering service called “Meals in a Zip,”
about an economic theory which asserts that consumers will purchase less of a product
at higher prices than they will at lower prices. She contends that the theory is incorrect
because over the past two years she has raised the price of her catered meals and yet has
seen a brisk increase in sales. How would you respond to Haslina?
A) Haslina is right; she has evidence to back her claim. The theory must be erroneous.
B) I will explain to her that she is making the error of reverse causality: it is the
increase in demand that has enabled her to raise her prices.
C) I will explain to her that there are some omitted variables that have contributed to an
increase in her sales such as changes in income.
D) Haslina is making the mistake of assuming that correlation implies causation.