The Six Year Itch? Whatever.

Incumbent Presidents tend to suffer losses in damn near every mid term election for whatever reason (see the figure below), so this sentence could be restated as “the party controlling the White House has lost seats in every midterm election but three since 1918 . . .”.  Given the relatively small sample size, this really doesn’t tell us anything.  A better way of looking at the question involves comparing the mean seat loss for the incumbent party in bog standard boring midterm years, and the hypothesized qualitatively different six-year itch years.  During such years, apparently “Anger, exhaustion and frustration tend to set in among voters as presidents approach the last leg of their final term. It happened to Franklin Delano Roosevelt in 1938 when voters recoiled at his New Deal reforms. ”  Of course, FDR would be re-elected in 1940, so that anger must have dissipated quickly.

In comparing the means between these two types of midterm elections, we have to settle on a measure of what is, and is not, a six-year itch election.  In terms of consistency, wikipedia lets us down; the brief entry on this topic includes 1974, by which time Ford had replaced Nixon, yet inexplicably overlooks 1998, possibly because it doesn’t fit the model.  In my analysis, I’ve settled on not settling on defining a clear measure.  Instead, I’ve chosen to start with a strict definition, and then progressively loosen the parameters of this six-year itch.  The above figure distinguishes such elections with a solid black border, and additional candidates have a thin border.

The table below compares the average seat loss for an incumbent party in standard (non-SYI) and SYI elections using five different measures.  A strict measure of SYI does what it says on the tin: a President must be in office at the time of the election six years from his first election.  From 1932 (20 total midterm elections), this limits us to five elections: 1938, 1958, 1986, 1998, and 2006.

Using a strict definition, there is no appreciable difference in average seat loss by the incumbent Presidential party in such elections.  The second column adds 1950 to the mix; one might argue that while Truman was not elected President in 1944, he did assume the office less than three months following the January 1945 inauguration thus giving Truman close to a full term in office prior to the 1948 election, but adding 1950 makes little difference.  The third column adds 1974.  Here, one has to argue that the voters either explicitly associated Ford with Nixon’s sins, considered Ford a mere extension of the Nixon years, or simply hadn’t noticed that Nixon was no longer president.  Given the pounding that Republicans experienced in 1974, this moves the means slightly, but still not convincingly.

Not satisfied?  The fourth column measures the SYI by including both 1942 and 1966.  In the case of the former, theoretically, why should FDR suffer from this phenomenon in 1938, but not even worse four years later?  If there is anything to this, then the itch really must have been festering in the minds of the voters in 1942 (as evidenced by the Democrats having lost 45 seats in that election).  1966 can be included for reasons similar to 1974 — LBJ, at least during 1964, was committed to continuing Kennedy policies in most domestic areas, hence his first “term” can be construed as a simple continuation of the Kennedy administration (which, in terms of names and  faces, it largely was).  Democrats suffered 1942 and 1966, so this does push the means even further apart.  Finally, the fifth column merges all this suspect logic by adding 1946.  Only now, do we see real daylight between the average seat loss of ordinary midterm elections and the special SYI elections.  Incidentally, this is also the only version of the five measures of SYI where the difference of the two means approach statistical significance (p=.086), but a) this assumes a one-tailed t-test, the use of which requires solid a-priori theory to suggest both the presence of a relationship and the direction of the estimate, b) these data are not random probability samples, and c) who cares?

Long story short: it doesn’t appear to exist.  There’s nothing really special about a President’s second midterm election that can not be explained by all the reasons why Presidents generally lose seats in any midterm election.  Visually, the only real pattern in the data illustrated by the figure above that is suggestive of the phenomenon is the period between 1952 and 1978, but for this to work one would have to loosen the definition of the measure such that both 1966 and 1974 merit inclusion.  1958, 66, and 74 do look different, but only one (1958) fits a rigorous definition.

What does this mean for 2014?  Nothing.  The Democrats will probably lose seats in 2014, but we don’t need a manufactured non-phenomenon to tell us that.  Alternatively, we can participate in some hard core wishful thinking and ignore oppressive historical precedent and choose to believe that the Democrats can retake the House in 2014 . . .