In constructing models, economists:

A. make simplifying assumptions.

B. include all available information.

C. must use mathematical equations.

D. attempt to duplicate the real world.

All of the above

Explanation:

A. make simplifying assumptions.

B. include all available information.

C. must use mathematical equations.

D. attempt to duplicate the real world.

all four options are what make a good economic model. assumptions are very important to simplify the underlying model. the information available including facts and figures is pivotal. Mathematical equations are used to prove a model. And attempt is made to duplicate the real world as nearly as possible.