Pretty much the standard things, as I understand it--land and opportunity. Increased survival of children and limited arable land had created a population crisis. Norway was a poor country, unable to support its growing population.
And there was still a pretty strong class system. It wasn't impossible for a poor boy to rise in the world, but it took singlemindedness and stubbornness. There was no celebration of the self-made man, as in America.
I don't know if you've posted on this before Lars; but I'd like to hear about why Norwegian immigrants came to north america in the early 1900's. (I've heard it was largely because they couldn't get land in the old country, but could get it here. My grandfather got homestead land in Manitoba, but it turned out to be poor land... and little more than a continual trial.)