Tuesday, July 24, 2007

Bush Approval: Three new polls, Trend at 29.6%
























New polls have moved noticeably above President Bush's recent low point of approval, though the current trend estimate remains below 30%. New polls have generally fallen at 30% approval and above, though one is as low as 25%. This change of trend was first discussed about a week ago here. Since then, the evidence for a shift in trend has mounted.

The ARG poll, taken 7/18-21/07, sets the low point at 25% approval, 71% disapproval. Gallup, done 7/12-15/07 got approval at 31%, disapproval at 63%. CBS/New York Times has two recent results: 7/9-17/07 has approval at 29%, disapproval at 64%, while the newest CBS/NYT poll of 7/20-22/07 puts approval at 30%, disapproval at 62%. Fox, 7/17-18/07 has approval at 32%, disapproval at 61%, while ABC/Washington Post 7/18-21/07 estimates approval at 33% and disapproval at 65%. So that puts four of the last six polls above 30% with only one in the mid-20s, where polling in late June was falling.

The trend estimate now stands at 29.6%, and the slope of the trend has clearly begun to bend from a steep downward trend to a less negative one. This is classic behavior of my standard "old blue" estimator. It takes a while to change direction, and while it does it slowly bends until it shifts direction entirely. In contrast, the "ready red" estimator is more sensitive and picks up on direction changes more quickly. The red line in the figure above shows a sharp change at just under 29% to a current estimate of just under 31% approval. The red line is often too sensitive, mistaking short term random noise for real change. However, we've now accumulated enough supporting polls to make me more confident that the upturn in the red estimator is probably real. At the same time, this does not mean the trend will remain as sharply up as the red estimator seems to suggest. That won't be known for a while yet, as more polls help define what the path of the next month or so is.

Recent polls have fallen above and below the trend estimate, and at the moment none of the last 10 polls constitutes an outlier, though there are both high and low polls rather close to the confidence interval limits. This range of results is also reflected in the very wide gray area at the end of the trend in the Bootstrap plot below. The wide gray area reflects our uncertainty about where approval is right now in a time of change in direction.

Finally, the last plot below shows the most recent 20 estimates of approval. The red dots trace out the clear decline, low point, and move back upwards in the "old blue" estimator. So even that estimator is feeling a change.