Sampling Canadian Manufacturers

Statistics Canada, Canada's national statistical agency, administers a monthly survey of manufacturing for Canada. This Monthly Survey of Manufacturing (MSM) includes information on such variables as sales of goods manufactured, inventories, and orders. The MSM data are used as indicators of the economic condition of manufacturing industries in Canada along with inputs for Canada's gross domestic product, economic studies, and econometric models. The sampling frame for the MSM is the Business Register of Statistics Canada. The target population consists of all statistical establishments on the business register that are classified as being in the manufacturing sector. The frame is further reduced by eliminating the smallest units of the survey population. As a result, there are 27,000 establishments in the sampling frame, of which approximately 10,500 units are sampled. Before the sample is taken, the sampling frame is stratified by both industry and province. Further stratification is then made within each combination of industry and province by company size so that similar-sized companies are grouped together. Selected establishments are required to respond to the survey, and data are collected directly from survey respondents and extracted from administrative files. Sampled companies are contacted either by mail or telephone, whichever they prefer.

Question:According to the information presented, the MSM sample is stratified by province, industry, and size. Do you think that these strata make sense? If so, why? Can you think of other strata that might be used in this survey?