Why are you implementing new statistical methodologies?
We periodically evaluate our statistical methodologies to support our mission to provide high-quality data to the public. Based on these evaluations, we inform our data users regarding any planned implementations of new statistical methodologies.
What is the impact of the new methodologies?
We believe that our new sampling and estimation methodologies will improve the accuracy of the weekly price estimates that we publish.
Did the historical data change?
No. We implemented the new sample for the data release on June 13, 2022. We did not revise price estimates that we published before June 13, 2022.
When did the new sample start?
The new sample started on June 13, 2022. The previous sample began in December 2011 and ended on June 6, 2022.
How many respondents report in the new sample?
The new sample, which started on June 13, 2022, includes about 590 diesel fuel outlets. The previous sample contained 403 diesel fuel outlets.
Why are weekly price changes not shown for the June 13, 2022 data release?
The official, published price estimates for June 13, 2022, are not directly comparable to the official, published price estimates for June 6, 2022, due to the different statistical methodologies used for the two samples. We present a comparison of separate price estimates produced from the two samples in a table for two weeks (weeks of May 30, 2022, and June 6, 2022). The price estimates from the new sample for these two weeks are preliminary and are not official statistics. As a result, data users should exercise caution when performing analyses based on these preliminary statistics.
Why are you publishing standard errors instead of coefficients of variation?
We are publishing standard errors, instead of coefficients of variation, to make it easier for data users to evaluate the precision of the corresponding price estimates, which are relatively small in magnitude.
Did you update the motor gasoline methodology?
No. The motor gasoline methodology was last updated on May 14, 2018.