Problems and Methods of the Sample Survey of Business

In business sampling, as in the general sampling problem, the over-all test that we apply to a sample design is that it shall yield the desired information with the reliability required at a minimum cost; or, conversely, that at a given cost it shall yield the estimates desired with the maximum reliability possible. A second criterion which we impose on the sample design is that the reliability of the sample results should be measurable. This requirement eliminates from consideration many superficially attractive sampling schemes which, while generally economical in both time and money, may lead to faulty conclusions. A particularly important characteristic of the distribution of sales of business establishments is that the distribution is highly skewed, with relatively few large establishments accounting for a substantial proportion of total sales. The sample design takes advantage of this fact and in so doing yields a sample of greater efficiency than would result from a sample of equal size if the distribution were normal. Various size classes are distinguished and the theory of optimum allocation indicates the number of stores to be sampled from each class. Large stores will be sampled from a listing of establishments, and the more numerous smaller stores will be sampled by cluster sampling. The appropriate sampling theory is given for measuring the various contributions to the sampling error, and for maximizing the information obtained per dollar expended.