Has any research been done to try and determine the percentage of the population that are able to detect obvious LLM-generated text?

Interesting question for sure, but for now the writing is just bad. So people might not know it's LLM prose, they just notice its poorly written and engage with the ideas less

> obvious

Who decide what is obvious or not?

majority of population dont read anything at all. Most they a read is perhaps labels and signs at a supermarket.