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Acknowledgments US Department of Transportation - BTS

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Survey responses are voluntary and are gathered from a panel <strong>of</strong> 175 utilities and 186 cogenerating companies witha monthly response rate near 95 percent. In 1992, an additional 71 new cogenerators joined the panel. This resulted,according to an FRB statistical analysis, in a decrease <strong>of</strong> the standard deviation <strong>of</strong> errors for electricity growth ratesfrom 3.0 to 1.9 percentage points. Overall, the estimates for total power use produce a standard error <strong>of</strong> about 0.5percentage points. The panel accounts for approximately 73 percent <strong>of</strong> industrial electric power use in the UnitedStates.The Survey <strong>of</strong> Current Business, published by the U.S. <strong>Department</strong> <strong>of</strong> Commerce, Bureau <strong>of</strong> Economic Analysis, isthe source <strong>of</strong> GDP estimates. Readers should refer to the source and accuracy statement for tables 3-1 through 3-5for information on GDP estimates.TABLE 3-11. Sales Price <strong>of</strong> <strong>Transportation</strong> Fuel to End-UsersThe U.S. <strong>Department</strong> <strong>of</strong> Energy, Energy Information Administration's (EIA's) Monthly Energy Review, tables 9.4 and9.7, provided price data, except for railroad fuel. Pre-1981 data were reported by the EIA from Bureau <strong>of</strong> LaborStatistics reports. Beginning in 1983, the EIA administered a series <strong>of</strong> surveys to collect data on petroleum prices,market distribution, supply, and demand. The EIA-782 series encompasses three surveys: 1) Form EIA-782A,Refiners'/Gas Plant Operators' Monthly Petroleum Product Sales Report; 2) Form EIA-782B, Resellers'/Retailers'Monthly Petroleum Product Sales Report; and 3) Form EIA-782C, Monthly Report <strong>of</strong> Prime Supplier Sales <strong>of</strong>Petroleum Products Sold for Local Consumption.EIA developed a method for comparing data from the new surveys with older information gathered by variousmethods. As a result, a number <strong>of</strong> adjustment factors were developed and used to "backcast" price estimates.Readers who require a more detailed description <strong>of</strong> this methodology should refer to EIA's petroleum datapublications web page (www.eia.doe.gov/oil gas/petroleum/pet frame.html) and the explanatory notes section.Changes in sample elements or collection methods may affect data continuity. Two regulatory changes affected datacollection in October 1993.The Clean Air Act Amendments <strong>of</strong> 1990 required that oxygenated gasoline be sold in thewinter months in ozone nonattainment areas. Thus, the EIA-782 forms were modified to collect information on fuelsdivided among conventional, oxygenated, and reformulated categories. Second, requirements for the production andselling <strong>of</strong> low-sulfur diesel were required and necessitated the separation <strong>of</strong> diesel fuel into high- and low-sulfurcategories. Moreover, surveys prior to October 1993 did not include propane. The EIA followed several differentsampling designs during two periods in the 1980s and thus, there may be some price estimate discontinuity forperiods between December 1983 and January 1984 as well as between August and September <strong>of</strong> 1988.Data CollectionThe 782 series occurs on a monthly schedule via mail. The 782A and 782C surveys reflect a census <strong>of</strong> about 115and 190 firms, respectively. The 782B samples about 2,000 firms. The EIA first stratifies by sales volume for the form782B survey to ensure that dealers with 5 percent or more <strong>of</strong> the market are captured with certainty. The remainingelements <strong>of</strong> the frame were assigned a probability <strong>of</strong> selection to form a 2,200 firm survey. These "noncertainty"companies were poststratified by geographic area and type <strong>of</strong> sales category.Data ReliabilityEIA has studied its sampling effects on reliability and determined that the sample size <strong>of</strong> 2,000 should yield a lessthan 1-percent price coefficient <strong>of</strong> variation in its estimates. Errors can arise because <strong>of</strong> nonresponse, but an EIA<strong>of</strong>ficial indicated that the response rates for the 1997-1999 782A, B, and C surveys averaged 95 percent, 86 percent,and 96 percent, respectively. Because survey data invariably contain incomplete data (because <strong>of</strong> reporting errors ornonresponse), EIA estimates or "imputes" missing data. Readers requiring imputation algorithms should refer to the782 series explanatory notes referred to above.TABLE 3-12. Price Trend <strong>of</strong> Gasoline v. Other Consumer Goods and ServicesData in this table were reproduced from the American Petroleum Institute's (API) Basic Petroleum Data Book. APInoted that data reported prior to 1981 was obtained from Platt's Oil Price Handbook and Oilmanac. Platt's is part <strong>of</strong>Standard and Poor's, and an independent third party organization that tracks the petroleum industry. Platt's reportedthe retail price <strong>of</strong> gasoline based on telephone interviews with gas stations in 55 cities. More detailed historical

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