Of course, you can state no reason, and avoid leaving evidence of your real motivations, which might make it harder to prove: if you fire someone because you discovered they're Polish and you hate Poles, they can only win an unlawful-termination suit if they can prove that was the reason.
Check out
http://en.wikipedia.org/wiki/Chinese_Exclusion_Act
http://en.wikipedia.org/wiki/Japanese_American_internment
for the most blatant forms.
(I expect he'll say it was just an example, but Freud would disagree)
US: 7.3%
Strong economies in europe:
UK: 7.5%
Germany: 5.2%
Denmark: 6.7%
Norway: 3.1%
Weak economies in europe:
Greece 27.3%
Spain 26.7%
Italy: 12.5%
You can't average countries with completely different governments and economies to produce a regional figure, just like an average of the US' and Mexico's (4.25%) would be equally meaningless.
The point I was trying to make was an economic one - if it is easier to fire a mistake (either for perfomance or business-reasons), then it makes you more likely to hire people.
Given the data you have no argument here. In germany it's fairly hard to fire someone who's out of probation. Still, we have a lower unemployment rate than the US.
Mind this article: http://en.wikipedia.org/wiki/List_of_sovereign_states_in_Eur... At least 14 European states with unemployment rate lower than USA.
https://en.wikipedia.org/wiki/At-will_employment