EIA’s Weekly Petroleum Status Report (WPSR) provides our most comprehensive data for weekly U.S. crude oil and refined petroleum product balances. Each week, WPSR provides detailed regional and national supply information on crude oil and major petroleum products used in the United States, including motor gasoline, distillate fuel oil, jet fuel, residual fuel, and propane. Our weekly estimates of inventories, refinery operations, and consumption are some of the most timely data series available anywhere to assess physical U.S. crude oil and petroleum product markets.
We generate weekly estimates of U.S. crude oil and petroleum product supply and disposition based on a combination of our weekly surveys, U.S. Customs and Border Protection (CBP) data, and modeled estimates. The surveys we use to develop our WPSR estimates, published on Wednesdays with information as of the previous Friday morning, collect data from about 1,200 respondents across the primary petroleum supply chain.
The weekly survey respondents are a sample selected from more than 3,000 respondents who report on our monthly surveys for data published in our Petroleum Supply Monthly (PSM). We consider the monthly survey data, which lag by two months, to be definitive because they capture information from all respondents as opposed to a sample used for the weekly estimates. As a result, we do not generally revise the WPSR data, which are intended to serve as a snapshot in time.
In our WPSR, we do not estimate the ultimate consumption of petroleum products by consumers. Instead, we estimate the movement of products through the wholesale distribution system before they reach the ultimate point of sale, such as retail stations. We use product supplied as a proxy for consumption, which is calculated as follows:
product supplied = production + imports - stock change - exports
Our surveys track production, imports, and stock changes; exports are estimated using data collected by CBP. Product supplied is the net amount inferred to move through the wholesale distribution system to retail outlets. Each term—production, imports, exports, and stock changes—carries some uncertainty, so any over- or under-estimation of these components directly affects the accuracy of our product supplied estimates.
In addition to the uncertainty in each term, our estimate of product supplied is not the same as the volume of the product sold by the retail outlets. When motor gasoline products are removed from the primary supply chain, they are then delivered to retailers who may hold them in their inventories until the products are purchased and then consumed, usually in vehicles. As a result, market events such as retail price fluctuations and anticipated spikes in refueling (such as holiday weekends) can lead to timing differences between our measure of product supplied and ultimate consumption. In summary, our measure of product supplied is a measure of product flowing to retailers, and demand is a measure of the product sold by retailers to final customers.
We recommend focusing on the four-week moving average given the week-to-week variability arising from our WPSR estimates. The moving average tends to represent recent market activity better than focusing on a single week’s estimate. Four-week moving averages are particularly useful for data series such as imports and exports, which can vary significantly week to week and are subject to timing issues because of how they are reported. As PSM data are released, monthly statistics should serve as a benchmark against which subsequent weekly series are compared.
Principal contributors: Warren Wilczewski, Owen Comstock