North and South korea only agreed on the joint industrial park because it drew in about 500 million dollars annually on cheap labor by north koreans because go figure. North Koreans get paid less than the average South Korean.
South korea manufactures all the cheap tech goods and North Korea sends in their "slave" labor workers.
This only works because North korea knows there is no loving way they'll be able to sell goods across the world unless it was under a South Korean label. So they work together and North Korea gets a huge share of profits.
Poll