Wisdom of the collective

I know I said I would read the book and then post about it, but I have to write down my thoughts as this idea just doesn't seem like it should work.  The problem I have is that the collective works selfishly.  I guess this is why betting on ideas or predictions helps because it shifts the focus of gain from getting what you want to getting the decision right.

However, in the case of deciding on the right policy, or the right rules, or laws, I don't think selfishness can be overcome.  One specific example I think of is the price of gas.  When gas was at an all time high, near $4 a gallon, people were making a noticeable difference in their driving habits.  I would argue that the best thing for people, and the world, as a whole is to drive up the price of gas so we are forced to use less.  Can anyone argue that using less gas is bad?  I think this is something that would be hard to decide as a collective because of selfishness.  In our democracy, this would also be very hard to implement as any politician that proposes a $2 hike in gas tax would surely be replaced at the first opportunity.

Another example would be benefits given to employees.  Could employees as a whole somehow come up with a benefit system that was good for the employees and yet would not drive the company into the ground?

How could we implement the "wisdom of crowds" and still get the "right" decisions?