In Defense Of Chart-Reading

After making some very valuable remarks on gentrification in DC, Ta-Nehisi Coates makes a remark that I think slightly resembles me:

Looking back on this, the thing that strikes is the importance of journalism. I think it's really easy to become the sort of writer who reads reports from Brookings and analyzes charts and graphs, without ever having to talk to the people captured in the numbers. People are scary in a way that think tanks are not.

I don't actually think it's all that easy to be a data-driven guy in a narrative-driven profession. But I think narrative is vital, I'm just not the best guy to do it. At the same time, I firmly believe that data is really important to this conversation. For example, was the appreciation in DC housing costs in recent years just a phenomenon of the nationwide real estate boom, or is there a real underlying trend here? Statistical evidence confirms that DC has in fact grown more expensive at a much faster rate than the national average:

Now here's a chart comparing how many thousands of units worth of building permits were issued in any given month nationwide to how many units worth (no thousands) of new permits were issued in DC:

To me, these charts tell an important story. When I speak to people in the city (which in fact does happen, since I do live here, reporting aside), they often see the fact that new development occurs in the same places at times when housing costs are spiking. Consequently, they often reach the conclusion that new development is causing price increases and that the best way to moderate price increases is to moderate the pace of new development. These charts indicate, I think, that this is a mistake. That both new construction and higher prices are caused by higher demand for housing, and that DC is experiencing an above-average rate of housing cost increases because we're experiencing a below-average rate of issuing permits for new construction. Approximately one American out of 500 lives in DC, so for every thousand new permits issues nationwide you'd like to see two permits issued in DC. But we haven't been anywhere near that in a long time.

This fact — the great difficulty of getting permission to build new housing units in the city — is driving a lot of people's anxieties about housing affordability. But it's not a fact that's all that widely understood, and lack of understanding means the same problem keeps arising without it getting addressed.