This is important for two main reasons.
First, if the two Koreas were to reunify, the richer country (South Korea) would have to absorb many significant costs of reunification. If North Korea and South Korea were to become one country, its government would be responsible for the welfare of all the people. If the North is much poorer than the South, this could be a significant problem. This is particularly true if the North has a large population compared to the South. Imagine it this way: what if the entire population of Mexico were to become part of Canada all at once. This would mean that the Canadian government would suddenly need to provide for many more poor people than it once did. If those people were too numerous and too poor, it would cause many problems. Of course, the unified Korean government would be able to use all of North Korea’s resources. But the issue is still important. In writing this essay, you will need to look at how much poorer East Germany was than West Germany and at the respective sizes of their populations. That will help tell you whether it would be harder to unify the Koreas.
Second, if the two Koreas were to unify, they would have to combine their economies. North Korea has been a command economy with almost no individual enterprise for decades. You will need to consider how hard it will be to integrate its workers with those of the capitalist South. Northern factories full of people who have always simply been told what to do will have to get used to working the way capitalist workers do. The North’s factories may not even be capable of competing in the world economy if they are too outdated. All of this will have a major impact on the possibility of uniting the two economies.