@Aleksandra200 Brian's example of "Have you stopped beating your wife?" is just the most common illustration of a loaded question (Fangfrage in German), which presupposes notions that may be untrue or irrelevant and funnels possible responses into the questioner's agenda.
Page 11 of your study asks: "If you were to buy a review or ask someone to write it, when would you do it?"
But you don't provide a "none of the above" option for hosts who would not consider committing review fraud. This is the equivalent of "If you were to beat your wife, which of these three objects would you beat her with?" I refuse to answer a manipulative survey.
Anyway, I think you might be reaching out to the wrong segment of the hosting world on this particular topic. These community forums are almost exclusively the domain of conventional hosts, i.e. people who list and manage properties they own themselves. The fake/mercenary reviews you're asking about do exist, but they're primarily found in the growing segment of Airbnb listings run by high-volume property managers. They have the capacity to create several guest accounts that look legitimate to dilute poor ratings, as well as fake "host" profiles to obscure the true scale of their operations. Airbnb treats these operators as VIP clients, with special features and privileges not extended to traditional hosts. Surveys viewed by a few dozen people on forum posts are not going to yield enough data to be statistically significant, but there are many ongoing investigations into the shadier would of property managers, so your research would be well served by contacting some of the journalists involved in that.
(I wouldn't expect to find much on an Airbnb-owned forum, though - it's a data-sensitive company, and the community members who have posted the deepest analytics on that have been unceremoniously banned from contributing).