A technical analyst believes that the Kondratieff Wave explains the longterm economic cycle for the United States. A weakness to this theory is that the:

a) sample size is extremely small, which makes it nearly impossible to test the legitimacy of the theory.

b) presidential elections, which often affect the economic cycle, occur every four years and these can disrupt the 18year cycle itself.

c) the theory has predicted more economic recessions than has actually occurred, which means that its success rate is less than would be expected.