Dr Leonid Petrov 
(one of my former teachers at Sydney U) notes that there are increasing signs or prosperity in NK. In the mid 1990's the DPRK population suffered from an aggravated famine that was likely linked to an industrial collapse. Western trade embargoes probably made the situation even worse, but since the administration would not reveal information, it may be a long time before we know the details.
But strangely, there seem some to be some increasing signs of prosperity.
There are new high rise apartments in Pyongyang, and more modern cars on the road. Money is being spent on what we could call entertainment facilities, and even the aging infrastructure built after the end of the Korean war seems to have some money being spent on it.
So where is the money coming from?
Dr Petrov notes in his Korea Vision web-site that an Australian mining consultancy has made an agreement with a DPRK agency to explore and develop rare earth mineral deposits that may be among the most important in the world.
If some of these deposits in adjacent areas are already being developed and supplied to the world market, it may explain where the finance is coming from for, not only the signs or prosperity mentioned in paragraph 2, but also for the nuclear research and development and the associated rocket programs.
Read more on Leonid's web-site at:
http://leonidpetrov.wordpress.com/2012/08/07/rare-earths-bankroll-north-koreas-future/
and scroll down to the second article on the page, headed: