[pp.int.general] Big Brother in NL?

[Richard Stallman]

    Taxes usually are based on "elasticity" considerations: a higher tax will 
    drecrease sales, so an x % tax increase does not produce an x % yield 
    increase, but less.

You have framed the question based on assuming that the motive for the
tax is solely to get revenue ("yield").  If the motive is to discourage
the activity, this "less yield" is actually success.

     People are so "addicted" to their car though, that a tax 
    increase in this field has hardly any influence on tax yield. So the effect 
    on behaviour influence is minor.

It has an influence, but the influence is felt over a longer time.
If people find out today that the gas tax will double, step by step,
over the next five years, they will start changing things.

I agree that more action is called for.  For instance, local train and
tram and bus lines need improvement.  Denser housing is needed so that
public transport is more useful and more economically feasible.
Bicycle lanes need to be made.  Lots of such changes are needed.  A
medium-term plan to make gasoline much more expensive will provide
impetus for all of them.

    We used to have a fligh tax which weas intended to reduce flying - again for 
    the benefit of reducing CO2 exhaust. It had no effect. Because it was a 
    national tax, people drove by car to nearby German or Belgian airports to 
    avoid the tax - and to produce more rather than  less CO2 exhaust.

Such airport-shifting will not occur if the tax covers all the
countries in the region.