If the first worker produces five custom picture frames a day, and the second worker produces five additional custom picture frames a day, it is clear that diminishing marginal returns have not yet set in.

The table above gives a nation's investment demand and saving supply schedules. It also has the government's net taxes and expenditures. When the real interest rate is 4 percent, the supply of loanable funds is equal to

A) $10 billion. B) $50 billion. C) $90 billion. D) $80 billion. E) $30 billion.

The government raises the sales tax on shirts. The tax is imposed on sellers. As a result, the ________

A) supply curve of shirts shifts leftward B) supply curve of shirts shifts rightward C) demand curve for shirts becomes vertical D) demand curve for shirts becomes horizontal