Electric Power Selling Price Indexes for Non-residential Customers (EPSPI)
Detailed information for September 2017
The Electric Power Selling Price Index (EPSPI) is a monthly series measuring the price movements of sales of electricity by distributors to commercial and industrial users.
Data release - November 14, 2017
The Electric Power Selling Price Index (EPSPI) is a monthly series measuring the price movements of sales of electricity by distributors to commercial and industrial users. The index is a useful measure of the change in the cost of electric power to the non-residential customer.
Reference period: The time period for which the EPSPI equals 100; currently this is the year 2014.
Collection period: Monthly
- Nuclear and electric power
- Prices and price indexes
Data sources and methodology
The universe for the EPSPI consists of all major generating and distributing utilities for each province in Canada.
Commodity specialists collect the various electricity charges on the internet and calculate a final bill by keeping the electricity usage constant over time. The resulting amount reflects the real price change of electricity.
This is a sample survey with a longitudinal design.
The main utilities in each province have been selected and their rates are tracked longitudinally.
Data are collected from other Statistics Canada surveys and/or other sources.
The collection of price information is carried out via internet collection as all data is publicly available. Follow-up by telephone and research on the internet for data verification is done, where necessary, to clarify information.
Major utility websites
All collected data points are checked by the commodity specialist and incorrect or suspicious data is verified on-line and if required with the utility.
Error detection is done during data capture and processing.
Imputation is generally carried out for missing data. In rare instances, utility websites may not be updated prior to the release of EPSPI results. In this situation, an estimate will be made to the utilities rates based on other utilities rate changes.
The collected prices are for non-interruptible power contracts with manufacturing, service and other Canadian industrial customers. This consists of two broad industrial categories of sales, less than 5000kW and 5000kW or more.
Free on board plant selling prices of electricity are obtained using selected bills collected monthly from all major generating and distributing utilities. The number of specified prices (bills) selected from each utility is determined by the various utility rate schedules. The prices collected are simulated transaction prices from each utility with fixed usage variables or specifications, to measure pure price movement. Specifications of these transactions are provided by the utility.
The weights for the EPSPI are derived from the 2014 volume of electricity delivered as reported to the Electricity Supply and Disposition Survey.
Weights are updated during a sample/basket update which typically occurs every 5 years.
The monthly index consists of a single estimate made during the reference month.
With the introduction of a new basket, historical estimates are linked to the new basket by maintaining the same historical period-to-period changes. This is done by calculating a link factor for each index series as the ratio of the new index series 2014=100 in the overlap period to the old index series 2009=100. This link factor is then applied to the old index series to bring it up or down to the level of the new index series.
The overlap period for the Electric Power Selling Price Index is currently December 2013.
The methodology was designed to control for errors and to reduce their potential impact on estimates. The data are subject to collection and processing validations on key variables and most non-essential data. Analysis at the index level is also performed at various stages of aggregation.
Statistics Canada is prohibited by law from releasing any information it collects which could identify any person, business, or organization, unless consent has been given by the respondent or as permitted by the Statistics Act. Various confidentiality rules are applied to all data that are released or published to prevent the publication or disclosure of any information deemed confidential. If necessary, data are suppressed to prevent direct or residual disclosure of identifiable data.
Collected data are converted to price indexes and data are released as such, so that it is not possible to identify the suppliers of raw prices.
Revisions and seasonal adjustment
With each release, data for the previous 12 months may have been revised. The indexes are not seasonally adjusted.
The statistical accuracy of the EPSPI depends on price data and weight information. Price data are obtained from a sample of utilities, while the weights are estimated using 2014 company distribution of electricity. Both kinds of input data are subject therefore to their own errors.
Though the EPSPI uses a sample survey methodology to obtain the necessary information, confidence intervals are not currently estimated, due to the longitudinal nature of price index series. Indexes for higher and lower levels of aggregation are considered to be statistically reliable.
- Changes to the Electrical Power Selling Price Indexes