>>Freak_+(OP)
Good question. I'd also assume that re-identification chances would always be of the form 100/k (k being the integer number of people who fit the bill)
>>Freak_+(OP)
Perhaps the risk that some of the data the probability is based on is wrong, e.g., "She fits the bill except they only have 4 children and the 5th is an entry error, so it's not her."
>>Freak_+(OP)
Co-author here. We designed a statistical model, which is never 100% sure a re-identification is correct. There is, e.g., a non-null probability that two individuals in the US share 5, 10, or even 15 demographics attribute.