While the Center makes every effort to assign an industry or interest group code to every contribution of $200 or more, it's not always possible to do that. PAC contributions are virtually 100% identified, but many individual contributions simply cannot be categorized. The charts below show how much of the member's contributions have been successfully coded by the Center, and how many remain unclassified.

• Those with no information about the donor's occupation or employer, or information so vague - like "businessman" or "self-employed" - that no code can be applied.
• Homemakers, students and others with no direct income, when they can't be connected with the family income-earner. (Where the wage-earner is known, their category code is applied to all non-income-earners within the family).
• Contributions where the employer is listed, but the Center wasn't able to categorize it. Though we try, we can't always identify the economic interest of every employer listed by donors. The Center uses a variety of reference materials that list companies by "Standard Industrial Codes," but due to limitations of time and staff resources, we can't get to them all. Others may not be listed in any phone books, business guides, or other resources, so their economic interest remains unknown.

Over the years, the Center has usually been able to identify about 99% of PAC contributions and about 65-70% of individual contributions for most candidates - at least by the end of the election cycle. We're always trying to improve those ratios, but the faster the money rolls in, the harder it is to keep on top of it. Please bear with us!