Post hoc ergo propter hoc

29 August 2009, 2020 EDT

I am usually a fan of Charles Blow’s work, but his latest op-ed seems to me a bit sloppy.

Blow claims that one reason Democrats, and President Obama in particular, may be having trouble convincing the country to sign on to large-scale health care reform is due to the public’s overall lack of trust in the government. This is a completely plausible hypothesis and one that I agree with, as the numbers regarding trust are incredibly low right now (~20%). What I take issue with is the way Blow points out a “peculiar quirk of recent American politics”; namely, that American’s trust in government has generally been lower following the election of a Democrat to the White House and higher after electing a Republican. Blow does not say that the Democratic administrations caused the decline in public trust numbers, but he might as well have given how the short piece is written.

Is it possible? Sure. But given the data and graphic he provides there are all sorts of reasons to doubt it is the case. At the very least, if he is going to imply such a causal relationship he should have provided a bit more discussion. Simply because low trust numbers followed the election of Democratic Presidents doesn’t imply causation.

The first problem is one of time: the data he bases his discussion on only goes back to 1976. Truncating the sample in this way gives us no perspective on whether this is an artifact of the data or whether it represents an actual pattern. To be fair, Blow no choice–the data is what it is. But the time frame distorts the possibility that the party affiliation of the President doesn’t matter.

Second, Blow gives us nothing to compare the data against in terms of control or alternative variables. Level of trust in government can be caused by numerous factors, including perceptions of Congress, bureaucracy, economic environment and trends, wars and foreign conflict, whether the country is moving in the right direction, etc.

Third, trust is built on repeated observation–people build up an image of whether someone or something is trustworthy based on past performance. That means feelings of trust take time to form and time to change. Additionally, the question asks about the government, not the President. In the United States, the term government has a broad meaning, unlike in parliamentary systems where it focuses on the ruling party. Given that, it is possible that any feeling of trust/distrust is dependent on both previous periods and the wider apparatus of government. We should be paying more attention to the general mood of the country prior to elections than on a single data point after a new President takes office.

Just to play around I collected data on the question of direction from the same poll that Blow pulls the trust data and graphed it side by side. The idea is that trust and feelings about the direction are likely related and do not move in lock step with single elections. Not surprisingly, there is a good fit between whether respondents see the government as trustworthy and whether they think the country is headed in the right direction (Correlation of Right direction and Always/Mostly trust is .8 and Wrong Direction and Some/Never trust is .83).

Moreover, if we map the elections of the last three Presidents on to the graph we notice something interesting.

Each President came to office after a long trend of either increasing or decreasing trust. For Clinton and Bush, this trend continued well into their first year in office. For Clinton, the trust and direction numbers began to turn upwards midway into his second year in office. For Bush, both sets of measures decreased after March of 2002. Obama took office after having watched the trust measure decrease from 55% to 17%. It took over 1 year to see the trust/direction numbers reverse during both the Clinton and Bush presidencies, so it is not surprising that we’ve only seen a slight up-tick in trust (+3%) during Obama’s first year in office. (Although it is interesting that the right direction measure has jumped since the recent election from 11% to 44% in only the first 8 months.)

Bottom line, Blow is right to point out that a massive change in a critical social good like health care is going to require trust on the part of the public. However, the peculiar quirk seems more a function of the timing of elections and less about the causal impact of a newly elected President.

[Cross-posted at bill | petti]