<p>Well, first of all, the 80% was a gross exaggeration, and I took it as such. Actual studies indicate that the US actually has a higher proportion of college-age students who actually attend college, and the US is clearly nowhere near 80%.</p>
<p>**The number of Koreanstudents in higher education had risen from 100,000 in 1960 to 1.3 million in 1987, and the proportion of college-age students in higher-education institutions was second only to the United States.*</p>
<p>[South</a> Korea - EDUCATION](<a href=“http://countrystudies.us/south-korea/42.htm]South”>South Korea - EDUCATION)</p>
<p>But, directly to your point, a country doesn’t really need any of its citizens to do any of those things that you mentioned. That’s where outsourcing and immigration (which can be viewed as the outsourcing of labor). For example, you don’t need anybody to grow your vegetables: you can just import them. Why not? That’s what countries like Singapore do. Singapore doesn’t actually grow any of its own food. {How could it? It’s just one big city.) It just imports everything. Similarly, the US imports much of its labor-intensive goods. </p>
<p>Similarly, you don’t really need to have your own citizens build your houses or fix your plumbing. You just bring in temporary workers from other countries to do that. Why not? That’s what the Gulf States (i.e. the UAE, Kuwait, Bahrain, etc.) do. For example, in the UAE, a bare 20% of the people who live there are actual citizens, and they occupy almost all of the professional class. The other 80% are non-citizens, usually from India or Pakistan, who are there on temporary work visas. They’re the ones who perform all of the manual labor. {It’s a good deal for those immigrants too, for they are free to leave anytime they want, but they determine that it’s better than being back in India or Pakistan.} This is akin to how many rich Americans hire (illegal) Mexican immigrants to clean their houses and cut their lawns. The major difference is that in the UAE, the system is legal. </p>
<p>Furthermore, you don’t even need to resort to even these tactics. Technology can be just as powerful - perhaps more so. The United States produces enough food to not only feed itself, but to also be one of the world’s top food exporters in the world. But what percentage of Americans actually work as farmers? About 1%, and declining every year. The US has the world’s best agricultural technology such that the country can produce ever-greater quantities of food with ever-fewer farmers. Similarly, you don’t really need lots of workers to run your manufacturing lines. Better production technology means more manufacturing output with ever-fewer manufacturing workers. The US produces more steel today - and with far fewer workers - than it did during the ‘Golden Age’ of steel. </p>
<p>Hence, I don’t see any theoretical reason why Korea couldn’t have up to 80% of population as part of a professional/technical class. Technological productivity, combined with outsourcing and immigration can supply you with all of the ‘labor’ (or at least labor-equivalents) that you need.</p>