Ideological Cartography

The New York Times published a fascinating article last week about the changing politics of physicians. The article reports that as more physicians abandon practices for salaried positions their politics have trended to the left. This trend is also present in the contribution patterns of health care professionals.

The figure below tracks the changes across time in the ideological giving patterns of four groups of health care professionals: surgeons, nurses, mental health care professionals (restricted to psychiatrists and clinical psychologists), and all other physicians. The trends track the mean ideological position (ideal point) of donors within each group. For each election cycle, I take the subset of donors from each group that gave at least once during that cycle and calculate their ideal points based on all donations made during that cycle and cycles prior. This permits the ideal point estimates to update with time.

Here are some helpful summary statistics for interpreting the scale. The mean ideal point for the entire sample of 2.5 million individual contributors (which includes health care professionals) is -0.16. The mean ideal point is -0.66 for Democratic candidates and 0.82 for Republican candidates.

Surgeons are by far the most conservative. They are also the group that was, on average, more conservative in 2010 than in 1990. The other three groups trend to the left in varying degrees.

I included nurses to emphasize that the industry has been changing as a whole. I also included psychiatrists and clinical psychologists to emphasize that differences between groups is probably better understood as a function of self-selection into a given profession than anything else. Whatever differences in pay and work conditions exist between mental health professionals and other physicians, they would not be sufficient to explain the differences in ideology. That mental health professionals are significantly to the left of nurses reinforces this point.

Although revealing, the trend line for physicians leaves out much of the story. The mean ideological position is relatively stable, but there is plenty of action in the distribution. The 1994 and 2010 midterm election cycles represent the closest thing to electoral deja vu that we can expect to see in our lifetimes. This makes these cycles useful points for comparison. The figures below show the ideological distributions for surgeons and physicians in 1994 and 2010. The distribution for surgeons fills out a little on the left over the years but remains unimodal. In contrast, the distribution for physicians changes quite a bit. Ideologically speaking, physicians have become more evenly divided and more polarized.

These figures can help address one of the paragraphs from the article that caught my attention:

“Dr. Cecil B. Wilson, the president of the A.M.A., said that changes in doctors’ practice-ownership status do not necessarily lead to changes in their politics. And some leaders of state medical associations predicted that the changes would be fleeting.”

I strongly suspect that Dr. Wilson is correct in his assessment. The link between doctors abandoning private practices for salaried jobs and their changing politics is probably overblown. I attempted to get at this question by dividing the sample into physicians who report being self-employed and physicians who report having an employer. I found only a slight difference between the groups. On the other hand, I sincerely doubt that the changes will be fleeting. The changes appear to be responding to generational shifts—in particular, the influx of women doctors.

I was curious as to whether the rightward jump observed during the 2010 midterms resulted from 1) donors that had previously given to Democrats shifting their dollars to Republicans or 2) increased giving by Republican donors relative to Democratic donors. In other words, was it a case of changing minds or changing wallets? For each year, I categorize donors into one of six categories based on their giving patterns in previous cycles.

• Strong Democrat – greater than 95% of donation dollars went to Democrats in prior elections
• Lean Democrat – between 60% and 95% of dollars went to Democrats  in prior elections
• Toss Up – between 40% and 60% of dollars went to Democrats  in prior elections
• Lean Republican – between 5% and 40% of dollars went to Democrats in prior elections
• Strong Republican – less than 5% of dollars went to Democrats in prior elections
• New Money – first time donors/had not given in prior elections

Each bar displays aggregate amounts donated to each party. For example, the bar labeled “Strong Dem” in the 2010 panel shows that donors who in previous cycles gave 95% or more of their dollars to Democrats, gave $41 Million to Democrats and $1.5 million to Republicans.

Partisan defections by Democratic donors had little to do with the 2010 shift in favor of Republicans. (In fact, the defection rate was greater for Republicans donors.) Increased giving by Republican donors and slightly reduced giving by Democratic donors account for the lion’s share of the swing. Republicans also received a larger proportion of dollars from first time donors than they had in the past. Republicans won 62 percent of the dollars from first donors in 2010, up from 44 percent in 2008 and 57 percent in 2006.

Lastly, it is worth noting that the overall rightward shift during the 2010 midterms is no larger than what we saw in other industries. Hence, I caution against concluding that the shift was in direct response to the Affordable Health Care Act.