system
Given the following post, respond as if you're commenting on Reddit:
human
Is it possible to have a shortage of low-skilled workers resulting from everyone being educated?

This is one of those questions that ive always been afraid to ask because I feel stupid for not knowing / understanding the answer, but it came up in my mind as I was listening to a lecture from Mankiw. 

In that lecture, he said that expanding education would decrease inequality because most of the US' inequality increase from the 70s onward was due to Skill-Biased Technological Change, since technology significantly benefited those with high skills, while those with low skills were more or less left out.

This makes sense, and I can definitely see why giving low-skilled workers more skills would decrease inequality (as it could help them capture the gains of technology)

but dont we need low-skilled workers, like in services, for instance? Dont we need taco bell workers, janitors, etc.? If everyone had a college degree or more, who would be / who would wanna work in these jobs?
gpt
No (and yes).
  
First thing is that the price of any good or service in any given market is determined by the supply and demand of that specific service. Labor market, like it or not, is not different. So education and salaries, even if they are correlated since there are factors moderating their relation (like specialization) do not have a causal relationship.


  
Second, there is a gap between giving somebody high education, and having that person working in jobs related to his high education experience. You may be a mechanical engineer and end up working as a bartender. This is happening in many economies around the globe.

When you consider a closed environment (let's say that we lock everybody up in X country and nobody can enter or leave) if you give high education to 100% of the population, the only thing that is going to happen, is that these skills will decrease in value as there will be an oversupply, and probably, lack of enough demand. On the other hand, low skilled jobs will be in high demand, so the salaries of the first will go down, and the salaries of low skilled jobs will go up, and eventually, you will have people that are engineers and rather work in a low skilled job. So, no, education does not cause that shortage by itself.


  
But, and here comes the trick, we don't live in closed environments. If high skilled employees are not paid enough, before going to work to low skilled manual jobs, many will leave the country, and you will have a brain drain.