Published May 1, 2003 | May 2003 issue
Of the 16,415 Ninth District Manufacturers a random sample of 2,418 businesses was drawn from the population.
Two mailings of a postcard survey were sent to each of the selected businesses. The first mailing was in mid-January, and a second went to businesses that had not responded by Jan. 31. The cutoff for survey responses was Feb. 21. A total of 608 usable surveys were received, for a response rate of 27 percent. Of the usable surveys, 69 were from respondents indicating that their specific location had no manufacturing on site; 162 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 4.2 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.