The Brookings Institution has published How Americans View Charities: A Report on Charitable Confidence, 2008, by Paul C. Light.  From the Executive Summary:

[P]ublic confidence in charities remains at contemporary lows. …  The percentage of Americans who said they had “a lot” of confidence in charitable organizations dropped from 25% in July 2001 to 18% in May 2002. The percentage that reported having “none at all” rose from 8% in 2001 to 17% in 2002.

A March 2008 survey … shows four patterns that should worry charitable organizations and sector leaders:

1. Charitable confidence has not risen significantly since it hit bottom in 2003.
2. Americans remain skeptical of charitable performance.
3. The considerable drop in the ratings of helping people poses a serious challenge to the sector’s distinctiveness as a destination for giving and volunteering.
4. Estimates of charitable waste remain disturbingly high.