Dave Naffziger's Blog

Martin Manley posted a fascinating post a few weeks back that looked at a number of economic measures by presidential party. They tell a fascinating story that runs counter to the (old?) conventional wisdom that republicans are better for the economy than democrats. Democratic presidents since the 1930s have out-performed republican presidents on measures such as GDP growth, stock performance, overall employment and on Gini index changes.

The graphs are built in a few ways that I consider unusual: they are bucketed by president, and so appear to treat 8 year terms the same as 4 year terms, and they include data from ww2 and a few years prior which brings the outstanding relative performance of Roosevelt into the analysis (most macro econ studies look at data from 1947 or 48 onwards).

So, naturally I was naturally curious to understand the data in a bit more detail. Manley cites Brad DeLong, who in turn cites Doug Henwood, Liscio Report. I know very little about DeLong, but a bit of quick browsing on his blog showed that he is, um, heavily partisan. So, I’m naturally wary. To make matters worse, the Liscio report appears to be a subscription service and I couldn’t find the data used on his site either. Given the partisan source, and the partisan biasing, I presumed the data in general was probably rigged and stopped thinking about it.

This evening curiosity got the better of me so I decided to try and redo the analysis using stats and date ranges that are a bit more logical/traditional. I used the BEA’s GDP stats (in chained 2000 dollars), and BLS data for unemployment & productivity (only available from 1948 onwards). The quick takeaway is that the graphs are definitely directionally correct: over the last 60 years, democratic presidents (and Congresses) have done a better job with the economy.

GDP
On a macro level, democratic presidents definitely trounced republicans.

The numbers are even more pronounced when you compare what happened when democrats and republicans each controlled both branches:

Employment and Productivity
Generally speaking, GDP growth is largely driven by both growth in employment and growth in productivity. In both cases, democratic presidents performed better than their republican counterparts:

I wonder why graphs don’t feature more prominently in campaigns?

Update
I added this graph based on a comment by B Raymond wondering how long a president’s economic policies take to have an impact. Frankly, it isn’t clear that their policies are having any increased or decreased impact over time at all:

Update 2
Rahul pointed me towards this really interesting analysis that shows income growth by party and income class.