Survey of Plant Capacity Utilization

How the Data are Collected

Data are obtained from establishments by means of a mail questionnaire or an electronic instrument via the Internet.

Sampling

The sample for the 2010 second quarter release was a new sample of establishments selected from the 2008 Business Register with updated information from the 2007 Economic Census. The sample frame contained approximately 210,000 manufacturing establishments and 13,000 publishing establishments. Sampling probabilities for the quarterly survey are assigned proportionate to the total value of shipments. The actual sample allocation is determined by the priority industry requirements specified by the Federal Reserve Board (FRB). The FRB’s requirements included 95 industry groups corresponding predominantly to the 4-digit NAICS industries or combinations. Each of these 95 industry groups is sampled independently to satisfy the total sample size constraint. The sampling procedure ensured that the allocated sample size for each industry group is exactly realized.

Estimation

The 2010 full production utilization rate for an industry is estimated based on those plants in the industry reporting both the actual value of production and the full production estimate. Simple weighted estimates of the two variables are formed by applying the plant’s sample weight to its respective values and adding these weighted values across the reporting plants. The utilization rate is formed as the ratio of the actual production weighted sum to the full production weighted sum. A similar procedure is used to estimate the national emergency production utilization rates, using the actual value of production and the national emergency production estimate.

Reliability of the Estimates

Since the estimates presented in this report are based on a sample survey, they may contain sampling error and nonsampling error. Sampling error is the difference between an estimate and the result that would be obtained from a complete enumeration of the sampling frame conducted under the same survey conditions. This error occurs because only a subset of the entire sampling frame is measured in a sample survey. Standard errors as given in Table 1 of this report are estimated measures of sampling variability. Nonsampling error is the difference between the result that would be obtained from a complete enumeration of the sampling frame conducted under the same survey conditions and the population parameter of interest. Nonsampling error encompasses all other factors that contribute to the total error of a sample survey estimate. This type of error can occur because of nonresponse, insufficient coverage of the survey universe, mistakes in the recording and coding of data, model error, and other errors of collection, response, coverage, or processing. Though nonsampling error is not measured directly, the Census Bureau employs quality control procedures throughout the process to minimize this type of error.