Presidential Approval Polls: The Effect of International Events

Presidential approval ratings have important consequences for legislative success and, of course, re-election. We also know presidential approval ratings, when they rise or fall below a certain level, signal future presidential successes or presidential struggles. An approval rising above or falling below 50 percent is an important benchmark.

There are many factors influencing fluctuations in presidential approval. One important factor is the response to major international events. A May 5^th Gallup report examined 48 events since 1950. They find the median increase is 7 percent in presidential approval.

Yet, in addition to the immediate changes, there is a question of whether the effect is permanent, long-lasting or temporary. To get answers to the duration of the effect, we need to use social science findings. And it turns out, when we determine the statistical properties of presidential approval, the answer is the level of this variable will return to where it was prior to the event. Moreover, there are other more consequential factors, such as the economy, which, because of the ongoing stream of information it provides, drive the level of presidential approval.

In other words, events act like a rubber band and snap back after being stretched, while upward or downward trends in presidential approval are sustained by other factors.

Tools in social science also allow us to calculate the duration. Consider the duration of the effect of the assassination of Osama bin Laden. A back of the envelope calculation of the statistical properties of presidential approval pointed to the effect lasting seven to 14 periods. How accurate was this prediction? A Gallup organization analysis shows the initial six percent jump in presidential approval (measured as a weekly average) fell back to its earlier level in about six weeks (May 1^st to June 15^th).

These social science tools aid in calculation, but what about context? What specific factors predetermined this temporary outcome? The Gallup data show only Republicans and Independents increased their approval of President Obama. Democrats remained at their high approval levels and did not move. Once other considerations such as the economy came back into focus Republicans and Independents reverted to their prior approval rates.

One final thought. The next time you hear a pundit saying an event will have a permanent effect on approval ratings, presidential success or even re-election, keep in mind the social science behind the analysis of this important political variable.

Author: This blog entry was written by Dr. Jim Granato, Director of the Hobby Center for Public Policy.