When they are asked — and not when they are paid — at least when it comes to one recent study of the Swiss:
In the early 1990s, Switzerland was getting ready to have a national referendum about where it would site nuclear waste dumps. Citizens had strong views on the issue and were well informed. Bruno Frey and Felix Oberholzer-Gee, two social scientists, went door-to-door, asking people whether they would be willing to have a waste dump in their community. An astonishing 50% of respondents said yes—this despite the fact that people generally thought such a dump was potentially dangerous and would lower the value of their property. The dumps had to go somewhere, and like it or not, people had obligations as citizens.
Frey and Oberholzer-Gee then asked a slightly different question. People were asked whether, if given an annual payment equivalent to six weeks’ worth of an average Swiss salary, they would be willing to have the dumps in their communities. So these people, who already had one reason to say yes—their obligations as citizens—were now given a second reason—financial incentives. Yet in response to this question, only 25% of respondents agreed. Adding the financial incentive cut acceptance in half.
The full story is here, and of course the actual answer might be different if you actually paid them. One way to read this result is in terms of signaling: if they have to pay me to accept it, it must be really bad. Another signaling explanation is that you look bad if you are willing to welcome a community harm in return for money. Another option is that “reasons compete,” rather than serving an additive function. The reason “being paid” may be crowding out the reason “being asked.”
Coming from another quarter, here is a dispiriting tale of commercialization, involving Alan Alda and Michael Sandel, among others.