The NBER BCDC memo and the data.
Final, revised data regarding the lead-up to peak, and after:
Figure 1: Nonfarm payroll employment (blue), industrial production (red), real manufacturing and trade sales (green), and real personal income ex.-transfers (black), all in logs normalized to 1989M07=0. Dashed line at 1989M07. NBER defined recession dates shaded gray. Source: FRED, NBER, and author’s calculations.
NFP peaks in 1990M06, industrial production in 1990M09, manufacturing and trade sales in 1990M08, and personal income excluding transfers in 1990M07.
From NBER, commenting using data available as of April 25, 1991:
CAMBRIDGE, April 25 – The Business Cycle Dating Committee of the National Bureau of Economic Research reached the judgment today that the peak of U.S. economic activity occurred in July 1990. The current U.S. recession thus began in July 1990, in the committee’s view.
The committee noted that the various indicators of economic activity normally used to determine the month of the business cycle peak were generally flat during the summer of 1990. Each of the major indicators reached a peak in a different month. During the summer, the month-to-month changes in these indicators were small.
Nonfarm payroll employment reached a peak in June. Real personal income peaked in July. Real manufacturing and trade sales pealced in August. The index of industrial production peaked in September.
As to the cause, well the Fed funds rate peaks in 1989M03, while oil prices only exceed the prior peak in 1990M08.