In: Statistics and Probability
An economist studied a large data set of Mexican consumer prices covering episodes of both high and low inflation. One of the goods in the study was coffee. When the inflation rate was low, an average of 3.4 changes in the price of coffee occurred each year. When the inflation rate was high, the price of coffee changed more frequently—an average of 9.2 times each year. [Source: E. Etienne Gagnon, Price setting during low and high inflation: Evidence from Mexico, International Finance Discussion Papers, No. 896 (City: Board of Governors of the Federal Reserve System, 2007).] The expected number of coffee-price changes in a 1-month period is_____
Assume that y, the number of price changes in any 1-month period, is described by a Poisson probability distribution with a mean equal to one of the values you just calculated (depending on whether the inflation rate is high or low). Then x, the number of months between consecutive price changes, is exponentially distributed with a mean of____
If the probability that the price of coffee stays the same for 2 months or less is about 0.44, is Mexico’s inflation rate high or low? a. Low b. High If Mexico is in a high inflation episode, the variance of x is____
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