The analysis and conclusion here are simple and, as our readers understand, quite predictable:

For the full decade of the 1930s, it averaged 2.6% — the same as the 1960s, a time of dramatic expansion in the public sector. Since then, it’s been mostly downhill.

To get back to that 2.6% average would mean an increase of $400 billion a year in public investment. (For details on the shortfall, and where the spending needs to be directed, see the American Society of Civil Engineers’ annual report on the topic.)

There’s no doubt the US could afford that. But our political system is completely incapable of formulating the problem.

In the 1930's we loved America and invested in infrastructure. Then the war...yada yada...and it took us a while to find our soul again but, thankfully, we did in the 1960's where we again spent like we meant it. Since then our government has been in the hands of the stingy or the downright cruel and our public infrastructure investments have fallen, as is visible in everything falling apart around us. Just spend more and — poof — problem solved (we can afford it).

Let me explain to you what is really going on because it's not what these charts purport to represent.

Always understand that when something is shown as a percentage of something else, you need to ask what is happening to that something else. In this case, everything is normalized to Gross Domestic Product (GDP). That means everything is divided by GDP, which has expanded greatly in every decade represented on the charts. When the denominator is growing, to keep the line flat the numerator needs to grow by the same amount. This has always baffled me when it comes to infrastructure. Don't we invest in infrastructure to grow the economy? If we're successful in making good infrastructure investments, shouldn't the economy grow way faster than our infrastructure spending grows?

More important than that little bit of intellectual silliness (people arguing that these are great investments then arguing that the rate should therefore increase as fast as GDP is silliness) is the notion that the charts are a NET investment.

Net Investment = Total Investment - Total Depreciation

So what you are seeing here is the amount we spent less the amount that what we already have depreciates in value. One way to look at this — the Jacobin way — is that we're not spending enough to keep up. Another way to look at this — let's call it the Strong Towns way — is that we've built so much stuff, most of it unproductive, that we're overwhelmed with depreciation (decline). Here's how it happens.

Let's consider a bridge costing $1 million. I'm going to leave out inflation, interest, etc... and just do a straight line depreciation (those things would make it look worse than what I'm showing, so I won't confuse things just to pile on). Assume the bridge is designed to last 20 years and then it will need to be replaced. So each year it depreciates 1/20th of the cost, or $50,000. As the table and chart below show, just focusing on one bridge there would be a positive Net Public Investment in year one and then negative every year thereafter. We built a bridge but, by Jacobin logic, we spent 19 out of 20 years shortchanging the public.