Friday, August 16, 2013

Fishy math in NBC's The More You Know about Graduation Rates

I've always had a soft spot in my heart for NBC's "The More You Know" public service announcements because they give short messages of encouragement which are a great break from typical advertisements.  When I saw this PSA, featuring Al Roker of Today, on Sunday during Meet the Press, I was vacationing with my family.  "What a great math problem to share with my classes this year," I exclaimed to my father.  He couldn't understand what I was talking about.  Watch for yourself and see if you took from it what I did.

Did you catch the math in there? "If we don't double the number of kids graduating from high school in the next 8 years, our country won't be able to compete globally." My knee-jerk reaction was, "Does he realize that's impossible?" We're already well above 50% of our students graduating. Take this article from NEA Today that cites the graduation rate at 74.7% in 2010.*  Doubling that, we'd graduate nearly 150% of the eligible students in a given year.  That's some fishy math. 

So, perhaps the answer here is that we need to look at the actual number of children.  If the birth rate is increasing significantly, the math could work out correctly.  I looked up the number of births in the US in 1992 (when students who graduated in 2010 would have been born), 1995 (2013 graduates), and 2003 (2021 graduates, "8 years from now").

1992 (class of 2010): 4,084,000 births
1995 (class of 2013): 3,892,000 births
2003 (class of 2021): 4,089,950 births

We can see that the birth rates dipped slightly in 1995, but are quite close in 1992 and 2003.  Let's take those children born in 1992.  Since 74.7% graduated:  4,084,000 births  • 74.7% = 3,050,748 graduates.  Unfortunately, I wasn't able to find graduation rates for years after 2010.  If we assume that graduation rates stayed relatively constant over the past three years, 74.7% of 3,892,000 births = approximately 2,907,324 graduates in 2013.  If we double this as Mr. Roker suggests, we'll need to graduate 5,814,648 students in 2021, which amounts to 1,724,698 more children than were born in 2003. 

What about immigrants?  Surely we have children graduate from American schools who weren't born in the USA.  Using some data from this site, I found that there were 40 million immigrants in the US in 2010 of which 6% were ages 5-17.  That equates to 2.4 million school aged immigrants or roughly 200,000 per grade.  If they all graduate, we still need to find 1.5 million additional students to graduate in order for the math to work!  It seems that my initial reaction was correct: there's no way to double the number of students graduating from high school in the next eight years.  Let's strive to increase our graduation rate and continue to reduce the achievement gap that we've been whittling away at for years. 

Going back to the original claim, I'd like to know what the threshold is for the USA to "compete globally."  Are we aiming for inclusion in the top 10?  Top 5?  First place?  I wasn't able to find that information on the NBC website.  You can compare high school graduation rates from around the world at this site.  Currently, Portugal and Slovenia are tied at 96% with the highest graduation rate and the USA ranks 21st.  If we were able to reduce the number of dropouts by half, our graduation rate would be about 87%, good enough for us to be tied with Hungary for 13th place. 

While I'm criticizing the math offered in the first sentence of the spot, I find there's a lot of truth in the rest of the spot and the text on the website below the video.  We do need to provide our nation's children with qualified, capable teachers.  Not only do we need to recruit new teachers to the profession, but we also need to support veteran teachers.  So while this clip touches on some valid points, I'd like to see the first sentence revised.  I suspect the good people at NBC meant, "We must decrease by half the number of students who don't graduate from high school on time."  Granted, that might be too verbose for a 15 second spot, but I'd still love an attainable goal!

Mathematically yours,
Miss B

* This Bloomberg Businessweek article lists the graduation rate as a percent of freshmen who graduate on time and has a nice graph to show graduation rates over time.  I won't be using 78% as I believe it excludes children who drop out prior to high school.

1 comment:

  1. YES just saw it on MTP, could not figure how it could be possible, my first thought was Is our graduation rate really that bad? Your comment points out there is room for improvement but it can't be doubled. It's weird that "The More You Know..." spits out these things. I've wondered before about whether there were actual facts behind these "PSAs".