The how do explain it's number 10 in GDP?
The 10th wealthiest nation on the planet has a crap economy? Nonsense
That it excludes many of its citizens is a different issue.
Mexico happens to have oil and makes money on a number of things that do not produce a real economy with jobs or a future for most of its people. However, ever being intent on doing an even worse job and shooting itself in the foot with its raving anti-Americanism, Mexico is now discussing doing away with the maquiladora system, which has really sustained certain segments of the economy.