Exactly -
@catware I'm not getting into an argument on isotropic radiation. I just can't be arsed to write down theory on the subject but suffice to say different countries have different laws governing the amount of rf that can be emitted by certain devices at certain frequencies.
EIRP and ERP are not the same thing and if you change the gain of the antenna (directional or not) but keep the power of the output stage the same then you are changing the EIRP (in some cases considerably).
I will not comment further on this thread.