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Quoctrung Bui of NPR’s Planet Money has mapped the most common job in each state based on U.S. Census Bureau data. The results might surprise you: Beyond a few farmers, secretaries, customer service people and computer analysts, America basically looks like a nation of truck drivers.

Why does truck driving dominate the map? It’s partially because of how the Census Bureau categorizes its data. First, Planet Money excluded two categories from the map because they are incredibly broad and vague – “managers not elsewhere classified” and “salespersons not elsewhere classified.” So it’s possible that the U.S. is actually a nation of vaguely defined salespeople.

In addition, the way the government counts truck drivers makes them a relatively large category. All truck drivers and delivery people are counted together, whereas primary school teachers and secondary school teachers are split into separate groups, for example.

But beyond methodology, the dominance of the truck driver reveals a few interesting things about the American economy. First, truck driving is more immune to the pressures that have affected American jobs in past decades, since driving can’t be outsourced or automated (at least not yet).

Second, regional specialization has been on the decline around the U.S., meaning the jobs that are needed everywhere in the country – like truck driving and school teaching – are moving up in the state rankings.

The map shows a few other fascinating (and somewhat tragic) trends. You can see the number of secretaries decline around the US with the adoption of the personal computer, and manufacturing jobs disappear due to globalization and technological change. The number of farmers also falls substantially, due to the increasing mechanization of agriculture.

You can see the full Planet Money post and animated map going back to 1978 here.

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