A year-long drought that destroys most of the summer's crops would be considered a:

Wealthy people will tend to have vertical labor supply curves

A) only if their income effect just offsets their substitution effect. B) only if their income effect is greater than their substitution effect. C) only if their income effect is less than their substitution effect. D) only if they don't have an income effect.

In a perfectly competitive industry we are likely to find

a. firms producing a wide variety of products b. barriers to entry c. no profit possible in the short run d. firms that do not advertise e. firms that can choose the price of their products