Productivity is a property of place

This is the most uncomfortable data point in the set. Researchers compared statistically identical workers (same age, education, experience, and sector), separated only by the country where they work.

This is called the place premium. If the same effort yields multiples of value depending on where it is applied, productivity is a property of the environment (machines, roads, energy, rules, institutions), not a moral quality of the person.

That is why the question “how hard does this person work” always comes with another one: “what is the ground beneath them like?”