I can't say whether illegals (because that is what they are) are included in radio ratings but they certainly should not be.
There is no definte data on the participation in ratings... and specifically the PPM... by illegals. However, knowledge and logic indicate that people who are undocumented would not participate in a survey where they have to give names, address, and family information to strangers. And, in the case of the PPM, grant access to the home in some circumstances.
Radio ratings and consumer research in general requires that all persons within the scope of a project participate in proportion to their distribution in the universe. Undocumented aliens and legal residents buy products, and that is all consumer research is about.
They are here illegally and so should not be included in radio station ratings.
Why? They are consumers, which is what advertisers wish to know about. The Census counts them, as well as they can. So ratings, which project a sample into the Census population universe, must contemplate their existence, whether they really particpate or not.
Hey, why not distribute diaries across the border to Canadian provinces or Mexican states.
Ratings are based on the ZIP code or place of residence per the market definition. In fact, when Arbitron was expanding in Mexico, they were going to consider a combined Tijuana / San Diego book, since that is the market.
Citizens there listen to some of our stations as well and they aren't breaking any laws to do so. Illegals should not be included as viable members of our society and advertisers should not be trying to reach them as though they live in some alternative society.
Ad agencies are not law enforcement organizations. And they care about anyone who would buy a product.