Mishkin • Instructor’s Manual for The Economics of Money, Banking, and Financial Markets, Twelfth Edition 239
ANSWERS TO DATA ANALYSIS PROBLEMS
1. A measure of real interest rates can be approximated by the Treasury Inflation-Indexed
Security, or TIIS. Go to the St. Louis Federal Reserve FRED database and find data on the
five-year TIIS (FII5) and the personal consumption expenditure price index (PCECTPI), a
measure of the price index. Choose “Quarterly” for the frequency setting of the TIIS, and
download both data series. Convert the price index data to annualized inflation rates by
taking the quarter-to-quarter percent change in the price index and multiplying it by 4. Be
sure to multiply by 100 so that your results are percentages.
a. Calculate the average inflation rate and the average real interest rate over the most
recent four quarters of data available, and the four quarters prior to that.
b. Calculate the change in the average inflation rate between the most recent annual period
and the year prior. Then calculate the change in the average real interest rate over the
same period.
c. Using your answers to part (b), compute the ratio of the change in the average real
interest rate to the change in the average inflation rate. What does this ratio represent?
Comment on how it relates to the Taylor principle.
2. A measure of real interest rates can be approximated by the Treasury Inflation-Indexed
Security, or TIIS. Go to the St. Louis Federal Reserve FRED database and find data on the
five-year TIIS (FII5) and the personal consumption expenditure price index (PCECTPI), a
measure of the price index. Choose “Quarterly” for the frequency setting for the TIIS, and
choose “Percent Change From Year Ago” for the units setting on (PCECTPI). Plot both
series on the same graph, using data from 2007 through the most current data available. Use
the graph to identify periods of autonomous monetary policy changes. Briefly explain your
reasoning.
See graph below. Periods of autonomous monetary policy change are characterized by a
decoupling of real rates and inflation rates. From the middle of 2007 to late 2008, inflation