Economic models are used primarily to

A few years ago, as oil and gas prices continued to increase, a growing number of Americans called for the United States to become less reliant on Middle-Eastern oil

Would it make sense for the United States to try to become totally self-reliant in the production of oil? Why or why not?

The table above gives the utility from pens and pencils. If pens and pencils both cost $.25 each and the consumer has an income of $2.25, which of the following combinations maximizes the consumer's utility?

A) 3 pens and 6 pencils B) 4 pens and 5 pencils C) 5 pens and 4 pencils D) 6 pens and 3 pencils