Stereotypes aren't necessarily true. There's for example a stereotype about Mexicans being lazy, but anyone who's actually taken the time to look at the statistics - and gotten to know any number of Mexicans, for that matter - knows that to be a complete fabrication.

The funniest thing about that stereotype is how can they simultaneously be lazy, yet also be taking all our jobs?

Stereotypes are just stupid and lazy thinking.

Schrödingers migrant: taking our job while being too lazy to work. Very common perception over here, too.

I seem to remember that one issue was that warmer climates had higher infestations of hookworms which manifests in ways that reinforce a "lazy and stupid" sterotype.

Lotta tech offshoring to Mexico these days over India, PI, etc. Perception is that the Indians generally get their skills through diploma mills while the Mexicans were generally more reliable and qualified. Better overlap with timezones -- Mexico City is on Central Time, and it's not hard to open a shop in Baja for Pacific Time -- and you also have access to the NAFTA TN Visa if you want to bring people across the border; no H1B visas headaches.

It is hours worked, not productivity. If a shopkeeper takes a three hour lunch and sits in the sun in front of his shop half the time but stays open from 08:00-20:00 according to the stats he’s working 12h days.

Which is correct, in any case. If he isn't doing anything else but "tending the business" even when there's no business because there are no clients, then he is "working".

What is not mentioned in the article is that productivity is much more important than the number of hours worked. By productivity, I mean output per hour worked, which is usually an estimation made from the total output of the country (GDP) and the numbers of hours worked by the working population.

Well, that's a very inadequate productivity metric imho.

How can two people with exactly the same output (say two doctors working a shift with similar number of patience) lead one to be 20 times more productive because one bills $400 per hour and the other makes that number in a week (such as in say Turkey).

That's a 40x difference in productivity.

You would usually use Purchasing Power Parity (PPP) such that comparison between countries is possible, because as you pointed, comparisons in absolute values between countries are not useful.

Thats because they refactored their economy during the debt crises.