The International Water Management Institute estimates that clean water could be provided to everyone on earth for an outlay of $______ a year beyond current spending on water projects.

In the short run a firm should shut down if it cannot

A) make normal profits. B) make economic profits. C) cover its variable costs. D) cover its fixed costs.

Frictional unemployment can be the consequence of

a. workers leaving existing jobs to find ones they like better. b. one industry declining while another is growing. c. changes in the working conditions offered by competing firms. d. All of the above are correct.