Published November 1, 2003 | November 2003 issue
Of the 16,415 Ninth District manufacturers a stratified random sample of 2,969 businesses was drawn from the population. For each state except Minnesota (see note below), the population was stratified based on employment size; the sample includes 100 percent of establishments with more than 49 employees, 20 percent with 5 to 49 employees and 3 percent fewer than 5 employees.
A postcard survey was mailed to each of the selected businesses. The mailing was in early August and a cutoff for survey responses was Aug. 29. A total of 562 usable surveys was received, for a response rate of 20 percent. Of the usable surveys, 90 were from respondents indicating that their specific location had no manufacturing on site; 108 surveys were returned as undeliverable or were unusable.
Survey results were tabulated for all manufacturers. The confidence interval for sampling error was calculated. The 95 percent confidence interval for the table of results for all manufacturers is plus or minus 4.1 percentage points. Results are also subject to errors introduced by other factors such as the wording of questions and differences between survey respondents and nonrespondents.
Note: The Minnesota Department of Employment and Economic Development produced and processed the surveys for Minnesota manufacturers, and the Federal Reserve Bank of Minneapolis conducted the survey for manufacturers in Montana, North and South Dakota, Ninth District counties in western Wisconsin and the Upper Peninsula of Michigan.