When the presidents of Brazil, Mexico and Argentina attended the G-20 meeting of the world’s biggest economies in South Korea last week, they should have taken some time off from the conference to take a look at the host country. They could have learned why South Korea has done so much better than their own nations.

Only five decades ago, South Korea had a per capita income of $900 a year, a small fraction of Argentina’s per capita income of $5,000 a year, Mexico’s $2,000, and Brazil’s $1,200. Today, South Korea has a per capita income of $28,000 a year, more than twice as high as Argentina’s $13,400 a year, Mexico’s $13,200 and Brazil’s $10,100.

What did South Korea do so much better than Latin American nations?

There are several explanations, including the fact that the Asian country hasn’t constantly changed its economic policies, stuck to a strategy of export-led development, and has long practiced a sort of state-managed capitalism that some economists credit for the emergence of its giant multinationals, such as Hyundai Motors, Daewoo and Samsung.

But virtually everybody agrees that one of the main reasons behind South Korea’s success was its obsession with education.

South Korea took off in the 1960s, when the United States and Europe drastically reduced their economic aid to the country, and South Korea’s economy plummeted. South Korea decided that it needed a well-educated workforce to increase its export income.

So heavy investments were made in education, science, technology and innovation. It wasn’t just a matter of government spending: South Korea’s government spends less than Mexico, Brazil, Argentina and most other Latin American countries in education as a percentage of its overall economy.

But instead of spending to create huge education bureaucracies that often employ many more administrative workers than actual teachers, South Korea developed an educational meritocracy with ultra-rigorous excellence standards.

Just as an example, South Korea’s school year is 220 days. By comparison, Mexico’s and Brazil’s official school years are 200 days, and Argentina’s, 180 days. But in many Mexican, Brazilian and Argentine states, the actual school year is only about 140 days when teachers’ strikes and unscheduled holidays are taken into account.

In addition, school days in South Korea are much longer than in Latin American countries. South Korean youths often study 12 or 13 hours a day, if you count the private tutoring institutes that large numbers of South Korean kids go to after school in order to improve their grades.

According to several studies, South Korea’s middle-class families spend about 30 percent of their income on private tutoring for their children. Much like China, South Korean families have a culture of investing in education with few parallels in the world.

Chung-in Moon, a Yonsei University professor and former South Korean diplomat whom I met at a conference last year, told me that “in Korea, parents don’t think twice about spending all their money for their children’s education. People sell their cows, their homes, whatever they have to send their kids to the university.”

And to study to become a school teacher in South Korea, students must be in the top five percent of their high school graduation classes. By comparison, thousands of teachers in Mexico still get their jobs by buying their positions for the equivalent of $10,000, regardless of their academic credentials or capacity to teach. Mexico’s own teachers union authorities admitted to me recently that the pay-to-teach system exists.

Not surprisingly, South Korea has become one of the world’s best performers in international math and sciences tests, and one of the most prolific inventors of new products. While South Korea registered about 9,600 patents in 2009, Brazil registered only 150 that year, Mexico 80, and Argentina 50, according to the U.S. Patent and Trademark Office.

My opinion: There are downsides to South Korea’s obsession with education, including relatively high teenage suicide rates, but South Korea’s impressive emergence from a poverty-ridden country that was way behind Latin America’s biggest economies suggests that the South Koreans are doing some things right.

The presidents of Mexico, Brazil and Argentina would have been smart to ask around, and take some lessons home.