CHAPTER 5.AGGREGATE SUPPLY AND DEMAND 119 Empirical 1. Earlier, we identified the 1973 OPEC oil embargo as a classical example of an adverse supply shock. Go to http://fred.stlouisfed.org and click on "Categories"; under "Prices," select "Con- sumer Price Indexes (CPI and PCE)." Then find the series "CPIENGNS" titled "Consumer Price Index for All Urban Consumers: Energy." The graph that is shown on the page should be from 1957 to the current year, with recession years shaded. Besides the date 1973 given in the textbook, can you identify on the graph other probable dates when supply shocks (oil shocks) took place? Give an example. d on the