They aren't paying directly, to prevent any kind of abuse to reap that reward by botting. Thus keeping response limited to humans only.
They do have a lottery tho, but only like 3 people will win. 10% of participants might get 5~10 USD worth amazon gift card(depends upon your response)
I took the survey, it seems like a study on how people take risks and their socioeconomic status.
Probably trying to find some kind of relation between these two and a few other variables(like your education, portfolio, etc)
I get this in Tor browser:
It worked fine on my private digitalocean proxy.