Reliable leading indicators of the business cycle are of great importance for policy makers, firms, and investors. It is therefore not surprising that economists set out on an intensive quest for such leading indicators, ever since the initial attempts of Mitchell and Burns (1938) for the US economy. This research has provided much insight into the construction, use, and evaluation of leading indicators, see Marcellino (2006) for a recent survey.
Reliability of a leading indicator variable includes aspects such as consistency and timeliness. By consistency we refer to the property that a leading indicator should systematically give an accurate indication of the future course of the economy and should not produce false turning point signals too frequently, for example. Timeliness means that in order to be useful, a leading indicator variable should have a considerable lead time with respect to business cycle turning points. Most of the currently popular leading indicator variables are believed to have a lead time between six and eighteen months. At the same time, it appears to be the case that many of these variables have a considerably longer lead time at business cycle peaks than at troughs. For example, the Composite Index of Leading Indicators (CLI) currently published by The Conference Board has led cyclical downturns in the economy by eight to twenty months, and upturns by one to ten months during the post-World War II period (The Conference Board, 2001).