The problem is that mankind is still expanding, especially in Asia. In China there is supposed to be nil unemployment, and I guess their government is very good at finding people something to do (even if it isn't very productive) but in a lot of other countries, especially India and parts of the old Dutch East Indies and French Indo-China, it is causing a lot of social unrest and resentment at people who have jobs. You have a well educated and trained workforce, but no jobs for them and no prospects, so they get very antsy at those who sitll have jobs, or the politicians who tell them there are currently no vacancies and then cut their benefits because there are too many people claiming them.
And then you have lots of migrant workers, determined to leave trouble areas where the prospects of life, let alone jobs, are not very high, or the 'econimic migrants' who have no hope of a job where they are and come to places like Britain because they are told it is better here (and often given a helping hand by other developed countries along the way who are just glad to see the back of them!). What happens then? They are a related problem for where there is no clear answer because a lot of time, money and precious resources is spent catching and sending them back (if one can!) only for them to simply try again.
