It largely depends on the kind of survey we're talking about. Essentially, it depends on the source. In many cases, we're using administrative data in order to drive forward an estimate, in which case we're getting a full census of volatility.
In other surveys, if I'm thinking about the monthly survey of manufacturers, the monthly retail trade survey, we're taking a look at response rates in the 80% to 85% range, and those are the economic production surveys that feed into GDP.
GDP itself is a composite measure. It's bringing in data from a range of different sources, so it's not possible to say there's a single response rate for GDP.