Cyclical unemployment a. has a different explanation than does the natural rate of unemployment. b. refers to the year-to-year fluctuation in unemployment around an economy's natural rate of unemployment. c. is closely associated with short-run ups and downs of economic activity. d. all of the above are correct.

White truffles are a very prized and rare edible fungus that grow naturally in the countryside near alba, italy. suppose that it costs $200 per day to search for white truffles. on an average day, the total number of white truffles (t) found in alba is t = 20x − x 2 , where x is the number of people searching for white truffles on that day. white truffles can be sold for $100 each. if there is no regulation, how many more people will be searching for white truffles than the socially optimal number?