See the rankings here.
Thailand is #13 overall, up from I believe it was #18 last year, so the recent chaos has not sunk us yet.
Singapore is #1, which I think it always is. New Zealand is #2, the US #3. Coming in rock bottom at #181 is the Democratic Republic of the Congo, but I don’t even see North Korea on the list. (“Korea” is #23, but obviously that’s South Korea.)
Japan’s #12 seemed a bit high until I looked at the breakdown: #64 for “Starting a Business”, but #1 for “Closing a Business”.
I would think in DR Congo it is easy to start a business… open a shop, sell things. No paperwork at all - chaos works like that.
North Korea… hmmm… I don’t think anyone can open a business except the government.
And I’ll bet there are some friendly e-mail contacts who would be glad to help you over the rough spots. 
It´s surprisingly easy to make a small fortune in Thailand, you just have to start with a big fortune…
And I’ll bet there are some friendly bargirls who would be glad to help with that. 
Good point. There is a very good book, I forget the name, that discusses how the problems of developing countries (particularly in Africa) are directly tied to how easy it is to do business. In countries with too many rules (or too corrupt of a regime to work with) often as much as 80% of commerce is in the informal economy. The problem with that being that your business can be seized or whatever at any time. So people have little motivation to invest and grow their businesses beyond the point of “this makes me enough to live on.”
I saw this personally in Cameroon. Once a year the tax guy would come, take a look around your shop, and just decide how much tax he should charge you. No doubt a good chunk of this went in to his own pocket. So people would keep their shops looking intentionally shabby and would not display their more valuable products.
The “official” rules were far too complex for anyone to rely on. Like, restaurant owners were supposed to have industrial kitchen supplies you couldn’t even buy in the country. We’re talking about restaurants that cook their food over open fires and charge fifty cents a meal expected to have sub-zero fridges. So business owners would just go on, pay the bribes as needed, and hope they can pay the right people enough not to get shut down.