The gyrating lines in Graph 1 represent average weekly hours for Oregon manufacturing production workers. Data for 1972 through 2002 are for manufacturing firms as defined by the old Standard Industrial Classification (SIC) system. Data for 2001 through 2011 are for manufacturing firms as defined by the North American Industry Classification System . Data (NAICS). Data are available for both industry systems for a 24-month period during 2001 through 2002, where the SIC data averages 0.9 hour higher than the NAICS data. The bold line on the graph is the 12-month moving average that adjusts the SIC data down by 0.9 hours per month.
Recent data over the past year reflect the general expansion of the economy and Oregon's manufacturing sector. The rapid rise in the workweek during that time is similar in magnitude to the gains seen following the recession that ended in 1982 and seen during the rapid economic expansion during the mid 2000s.