We use a rolling window for lobbying disclosures in an attempt to capture the full quarter’s lobbying expenditure. Large lobbying disclosures for a company on the same issue are often done quarterly with a semi-consistent interval, so there is potential for a company to move out of the rankings for one (or more) rebalance periods if the two disclosures are spread out, and conversely for a company to move into the ranking during a rebalance window if the two disclosures are closer together.
Lobbying disclosures are filed under a company’s legal name, and are not mapped to tickers at the source. Because of this, there is a risk of mapping lobbying disclosures to the wrong company, or missing disclosures that are filed under a subsidiary or other name. While we have taken steps to mitigate this risk, it presents the possibility for erroneous data.