Rhee Knows Nothing About Inequality

I finally got around to watching failed author Michelle Rhee's appearance on Real Time with Bill Maher from last night. Maybe I'll say more about it later, but I wanted to get to one of the little data points she threw out last night:

MAHER: "I have some statistics here on studies they have done on schools here in America, and it doesn't really indicate that it's the schools that is the problem. I mean, we hear all the time that America is falling behind, but in three major international tests - there's the one, Progress of International Reading and Literacy Study - I'll just give the two - the Trends in International Math and Science... 

Students in U.S. schools where the poverty rate is less than 10% are first in reading and science in the world." 

RHEE: "Compared to the average kids in the other countries - you can't do an apples to oranges comparison. If you look at the top quartile of kids in our country by income level - right, so the most privileged kids - and you compare them internationally to the top quartile of other countries, they rank 23rd."

My ears pricked up at this one, because I wrote a series of posts last year about this very topic: here, here, here and here. Let me summarize:

In 2009, the National Center for Education Statistics released a report that included this table:

That score of 551 was higher than any other country in the world - including countries where the child poverty rate is way under 10%. Mel Riddile pointed out than most developed countries have child poverty rates far lower than the United States, and that accounts for most, if not all, of the difference between the average score of the U.S. and other countries. Diane Ravitch approvingly linked to Riddile's post.

What Rhee said on Maher's show last night is a talking point developed by writer Amanda Ripley, designed as a direct response to Ravitch. As I showed in my posts, however, Ripley actually misstated what Ravitch said. You can go back and revisit the entire thing, but here's the takeaway as it relates to Rhee; I started this post by comparing the difference between the 75th percentile in socio-economic status and the 95th percentile:

So the gap is further apart between 75th and 95th percentile kids in SES than any other country but Israel; in other words, kids in the US benefit more from being higher up the SES ladder than in most other countries. (And look who has the smallest differentials: envied Finland and Korea. Huh.)

Let me show this another way. Let's compare the US score for kids at different SES percentiles to the top scoring country in that percentile. How far behind do US kids fall?

In the 10th percentile for SES - the 10% of the poorest kids in each country - Korea's kids do the best in the world. And they beat the US's poorest kids by over 60 points.

But in the top 95th percentile for SES - the 5% of the richest kids in each country - New Zealand's richest kids do the best in the world. And they beat the US's richest kids by only 22 points.

In other words: wealth alone cuts the gap between our kids and the top performers in the world by two-thirds.

But hold on! This really isn't a good comparison; it doesn't account for outliers. Go up to my first graph: New Zealand beats the next best scorer in the 95th percentile by 10 points. This suggests there may be some anomaly that's creating statistical noise and giving NZ an unfair advantage; maybe the test had a bunch of hard questions about counting kiwis or something...

Let's do this: take the top eleven overall scorers for all kids (the US ties with Poland and Iceland at #12, but we'll keep it simple and exclude them). Average the scores for those top eleven at each percentile for SES. Then look at how the US compares; that should mitigate against outliers a bit. How are we doing?

And look at that: the 20-point differential at the 10th percentile disappears to next to nothing at the 95th percentile. What does this mean?

It means kids in the US are penalized MORE for being poor or even middle class than kids in other high-scoring countries.

So when Rhee says: "Our top quarter wealthiest kids suck compared to their top-quarter wealthiest kids," understand that this is not true for the top 5% wealthiest kids - the real "rich kids." When you get that high up on the economic ladder, the differences between countries virtually disappears.

It's Rhee who isn't comparing "apples to apples": she assumes that the distribution of wealth within the top quartile of different countries is similar. But test score distributions within that quartile are not similar: there is a greater difference in tests scores, as distributed across socio-economic levels, in the U.S. than almost any other developed country.

There is, in fact, a correlation between a country's overall test scores and its relative level of inequality. And the U.S. has embarrassingly high levels of inequality:

Walt Gardener has more on the GINI index and education.

Michelle Rhee is very slick, but her nonsense simply doesn't stand up to close scrutiny. Poverty is not an "excuse" - it is a reality. The United States has shamefully allowed far more of its children to live in poverty than most other developed nations; further, we have allowed inequity to grow so large that it actually affects the gap in test scores between the very wealthy and the middle class.

This, and not "bad teachers," is the source of our educational failings. Don't let Rhee or anyone else try to convince you otherwise.