> That's less than it seems though, given that the US population has grown with over 0.7% per year for most of those years.

So what? Why does government have to grow proportionally with the size of the population? This is not a given in any other organization.

You generally expect the size of an organization to scale with the scope of its activities, especially if its activities include "healthcare" and "building roads."

"Scope of activities", maybe, but there's no inherent reason that has to be equal the rate of growth in the population. You'd hope that government becomes more efficient over time.

Private organizations have profit constraints, and they're constantly striving to become more efficient, cut what doesn't work, and so on. Government has no such constraint.

The government has become more efficient over time and its size as a percentage of the population has reduced as the population has grown.

Government does have a constraint like that - it has to remain solvent. A government as powerful as the United States has many tricks it can use to do that, but at some point even it cannot do anything it wants.

To compare, Walmart employs over 2M workers, and as efficient as they are, they still need to scale with the size of their business scope. Whether it's a linear scale or a log scale, they need more and more people as they do more and more.

The fact that the same order of magnitude number of people can administer an entire country as the number of people that it takes to administer a bunch of stores is actually remarkable.

> Why does government have to grow proportionally with the size of the population?

It does not, and did not:

* https://fred.stlouisfed.org/series/CES9091000001

I'm responding to the parent's implicit assertion that the government should somehow naturally grow with the size of the population.

Arguing that it historically has not done so only makes my point. Nor is it an argument that government should not be smaller today.