What does it matter what stack of money the spending comes from? Here in DC, the Metro is funded by the federal government and the states and the localities. Can we say “Metro funding is too low!” by looking at just the federal part and pretending that the other spending doesn’t exist?

Federal “discretionary spending” just means that money is allocated by appropriations bill rather than statutory formula. But the money is totally fungible—Congress can just as easily change the formula as it can change the appropriations bill.

Likewise, it makes no sense to ignore all the state spending. Defense is the job of the federal government, while social services are the job of the states. We spend a trillion dollars on education every year—almost none of that shows up on the federal discretionary budget. Does that mean you can ignore that spending? It comes out of everyone’s pockets and goes to teachers just the same as if it had been allocated by a federal appropriations bill.

There are legitimate arguments for cutting the defense budget. But the purpose of comparing defense costs just to discretionary expenditures is to deceive people about how much could be achieved by cutting the defense budget. If we cut defense expenditures to the NATO target, we would save $200 billion annually. That would fund some programs. But government spends more than $6.5 trillion a year already on non-defense things. Another $200 billion won’t be game changing.

I suspect one reason politicians fixate on the defense budget is that it provides a seemly large pot of money to fund social programs, distancing those proposals from the idea of tax increases. But that only works if you squint and don’t do the math. We would have to spend $1.4 trillion more annually to match Germany’s public spending as a percentage of GDP. And there is no reason to believe we’d be able to implement a European-style welfare state any more efficiently than Germany.

There's a lot to unpack here and honestly I've got stuff to do right now so I can't get into it. But I will mention one thing...

> We would have to spend $1.4 trillion more annually to match Germany’s public spending as a percentage of GDP. And there is no reason to believe we’d be able to implement a European-style welfare state any more efficiently than Germany.

The efficacy of social programs doesn't scale linearly with funding. That's not how you do the math. Each dollar spent has cumulative power. In truth we wouldn't need to come anywhere close to $1.4 trillion to match the impact of Germany's social programs.