The OECD has published CLIs since 1981. The CLIs are aggregated time series and up to December 2008 they have been compiled using a modified version of the method developed by the US National Bureau of Economic Research. Starting from December 2008 this approach has been replaced by the Hodrick-Prescott filter. For most countries, total industrial production (IIP) is used as a proxy measure (or reference series) for GDP as historical turning points of IIP have coincided with those of the entire economies.

The CLI comprises a set of component series selected from a wide range of key short-term economic indicators to ensure that the indicators will still be suitable when changes in economic structures occur in future.

While theory says that a turning point in the CLI signals a turning point in the reference series, such turning points, in reality, are determined by a complicated process. Therefore, one often needs to wait for several periods to draw a more definite conclusion. A useful way to exploit the information in CLIs is to take their year-on-year growth rate.

Component series and turning points  are listed on this website. Terminologies are explained in the glossary . OECD work on CLI regarding methodology and revision, and the relevant papers can be found in the online Sources and definitions.
Schedule for CLI updates