4. 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 a measure of the price index, the personal consumption expenditure price index (PCECTPI). For the frequency setting for the TIIS, choose "quarterly," and for the units setting on (PCECTPI), choose "Percent Change From Year Ago."

Plot both series on the same graph, showing data from 2007 to the most current data available. Use the graph to identify periods of autonomous monetary policy changes. Briefly explain your reasoning.