(Guest Post by Matthew Ladner)

Last year I was reading the comments section of a newstory online, and came across a comment from a public elementary school teacher. She was complaining that she had 34 students in her classroom.

So let’s do the math. The statewide average spending per pupil in the state: $11,000. Total revenue generated by this classroom = $374,000. Let’s assume the teacher gets a total compensation package of $60,000 including benefits. The question becomes- what did they do with the other $314,000?

Ah, that was what the teacher was really angry about. Her elementary school had 8 teachers in “non-classroom assignments.”

I don’t have a problem with 30 some odd kids in a classroom. It’s been done, and is being done. Remember?

Many insist that the period depicted by this photo constituted the “good ole days” of education. Jay and Greg have felt compelled to dispel the myth of the lost golden age of public education, back in the good ole days, when public schools were far more effective than they are today. The truth, of course, is that NAEP scores for 17 year olds are flat as far back as you can take them.

What has not been flat- public school spending- adjusted for inflation per pupil has steadily increased even while test scores have stagnated, even while Americans have become wealthier and poverty has declined.

Of course, there is no single explanation for this trend, but certainly the national obsession with lowering average class sizes must be viewed to have been an enormously expensive academic failure. Consider the international evidence:

Really big classes in Asia, really small in the United States. However, when it comes to achievement:

The average South Korean seventh-grader scores 21 percent higher than the average American on seventh-grade mathematics, despite having much larger average class sizes. While a variety of factors contribute to the relative deficiency of American public schools, many scholars are beginning to suspect the main factor is the relatively inferior average quality of American teachers.

In How the World’s Best Performing Schools Come Out on Top, the international management consulting firm McKinsey & Company point squarely at teacher quality as a key variable in explaining variation in international academic achievement. In its findings, McKinsey quoted a South Korean policymaker who noted, “The quality of an education system cannot exceed the quality of its teachers.”

McKinsey found that the top-performing school systems around the world recruit their teachers from the top third of each graduating cohort. Moreover, South Korean schools draw from the top 5 percent of college graduates. Larger class sizes create the resources to pay South Korean instructors much higher salaries.

The Organisation of Economic Co-operation and Development measures relative teacher pay by comparing the average salaries of teachers with 15 years of experience with a nation’s gross domestic product (GDP) per capita. A high salary compared with per capita GDP suggests that a country invests more of its financial resources in teachers and suggests a relative prestige of the profession. By definition, the average person in each of these countries will earn a ratio of 1. Figure 3 compares teacher-salary-to-per-capita GDP for the United States and South Korea.