Sample Design*Sample Frame*New Industry Estimates*New Data Items*Data Items for Improved Estimation*New Geography*Discontinued Data Items
Sample Design. The MECS has increased its sample size by roughly 40 percent since the 1991 survey, increasing the designed sample size from 16,054 establishments to 22,922. This increase in size and change in sampling criteria required a departure from the Annual Survey of Manufactures as the MECS sampling frame. For 1994, establishments were selected directly from the updated 1992 Census of Manufactures (CM) mail file.
Sample Frame Coverage. The coverage in the 1994 MECS is 98 percent of the manufacturing population as measured in total payroll. The sampling process itself provided that level of coverage, and no special adjustments were used to increase it. The 1991 survey had identical coverage, whereas the 1988 survey was statistically adjusted to cover 100 percent of the population. Therefore, many of the potential sources of bias that pertained to the 1988 survey estimates are not relevant to either the 1991 or 1994 survey. Because of the difference in sample coverage, care must be exercised when comparing absolute quantities among the three surveys. Small differences might be attributable to coverage rather than real change.
New Industry Estimates. The nearly 7,000 increase in the number of establishments sampled has allowed EIA to publish separate estimates for 52 industries and industry groups in addition to the 20 larger major groups (2-digit SIC). In 1991, there were 42 industries and industry groups published; and in 1988 the sample design permitted only 10 industries for which separate estimates were publishable beyond the 20 major groups. Also, for the first time, the 1994 consumption report presents estimates relating to the number of manufacturing establishments.
Additional Data Items for Improved Estimation. In 1991, EIA recognized a potential for overestimating energy source quantities in industries that produce and sell energy sources and corrected for such overestimation by collecting energy shipments from sample establishments. This correction is required when an manufacture uses an energy source as an input to a process (i.e, feedstock), produces another energy source as a result of that process, and then sells or transfers the produced energy source to another establishment. The quantity of the receipt in the second establishment would duplicate the feedstock use in the first. Part of the solution has been to estimate consumption in petroleum refineries differently from other industries (see section entitled "Feedstocks and Offsite-Produced Fuel at Petroleum Refineries" in the of the 1991 consumption report). To correct the problem for other industries, the MECS, in 1991, began collecting shipments offsite of energy sources produced onsite (see "Development of the Data File" in this Appendix B of the 1991 consumption report). EIA has continued to correct for energy shipments from manufacturing establishments in 1994. In addition, estimates of energy shipments appear in Table A1, First Use of Energy for All Purposes, of the 1994 consumption report.
New Data Collection Sections. Survey collection forms now include sections on natural gas industry deregulation— service rates of natural gas purchases; supplies, transportation and other costs associated with non-LDC natural gas purchases—actual fuel switching occurring between natural gas and residual fuel oil, types of cogeneration technology in use by manufactures, square footage of manufacturing floorspace, and energy management activities (sponsored by electric utility; self; 3rd party; Federal, State and local government). As a one-time collection of establishment activities, EIA investigated the methods that manufactures most commonly used to purchase, and make modifications to, electric motor systems.
New Geography Level. In part, the approximate 7,000 establishment increase in sample size provides for reliable estimation of energy consumption at the geographic level of 9 census divisions.
Discontinued Data Items. Since the 1991 MECS, several items have been eliminated. Two data items concerning onsite electricity generation were discontinued. These were interconnection status with an electric utility and whether the establishment was a Qualifying Facility under the Public Utility Regulatory Policies Act of 1978. These items were no longer required because they are collected as part of a new survey, Form EIA-867, "Annual Nonutility Power Producer Report."
EIA Introduces Energy InfoDisc; New CD-ROM Provides Instant Access To Comprehensive Energy Data,Analyses
File Last Modified: 4/1/97