From this Bank of England paper on using search data:
???In contrast to most traditional survey methods, they are collected as a by-product of normal activity, rather than requiring individuals or firms to respond to survey questions after the event. This can avoid problems associated with non-response or inaccurate responses. And it also means
that information is continually collected on a wider range of issues, rather than just on a few pre-determined questions. As a result, search data can help analyse issues that arise unexpectedly.???
This way they can tell when the economy is pregnant…