How would you suggest to do a survey across countries? Is it impossible?

Now you've hit on a problem I can get my mind around! The simple linguistic challenge of asking identical questions, with identical cultural and emotional content across cultures is impossible. Due to the same factors they try to measure here.

It's analogous to Heisenberg's uncertainty principle.

Excellent point.

"It Can't Be Just About Us"
--Frank Schnittger, ETian Extraordinaire

Culture is often invisible to the person who is embedded in it, but controls and constrains their actions, and guides their beliefs.

Take the idea of an equality/efficiency tradeoff.  Where the idea is ingrained in the culture (US/UK) attitudes towards things like labor unions and other things that might bring about a more equal distribution of wealth are effected by this underlying idea in culture.

What you get when you do a survey that shows resistance to progressive taxation, etc, is what people believe, not why.  

And culture is at heart, the why factor.

And I'll give my consent to any government that does not deny a man a living wage-Billy Bragg