Glossary
Publication lag
Publication lag is the gap between the month an index measures and the date the statistical agency releases that value. A clause has to say whether it uses the preliminary figure available at adjustment time or waits for the final, revised one.
Also called: reporting lag, data lag, release lag.
Producer and consumer price indices are published two to six weeks after
the month they cover, and early figures are often revised for one to four
months afterward. So on 10 April, a clause that says "use the March index"
cannot be run: March is not out yet.
Clauses handle this two ways. A fixed offset says "use the index for the
second month before the adjustment month", which is always available. A
preliminary-versus-final rule says which version governs if the value is
revised after the adjustment is calculated, and whether a revision
triggers a true-up.
Ignoring publication lag produces invoices that cannot be issued on time
or that get reopened when numbers move.
See how publication lag works,
true-up, and
averaging window.
Related terms
The reference period is the year a statistical agency sets an index equal to 100, so all other values read as a percentage of it. It is a property of the index itself, not of any contract, and it is not the same as a clause's base period.
A successor series is the index a clause switches to when its named series is discontinued or restructured by the statistical agency. A well-drafted clause names the successor, or a method for choosing one, in advance.
A true-up is a later correction to a price adjustment that was calculated from a preliminary index value, once the final revised value is published. The difference is billed or credited in a subsequent invoice.
WPU and PCU are the two BLS Producer Price Index series-code families. WPU codes track a commodity by what it is; PCU codes track the output prices of an industry defined by NAICS code. Many materials appear in both, at different values.
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