A recent Gallup poll shows that, despite fears over the economy, the number of Americans experiencing "a lot of happiness and enjoyment" increased by one percentage point fro 2009 to 2010.

From "Americans Happier, Less Stressed in 2010" by Dan Witters.
Published Jan. 4, 2010 at Gallup.com
http://www.gallup.com/poll/145457/Americans-Happier-Less-Stressed-2010.aspx

1) These surveys were conducted by Gallup Polls.
2) No sponsors were reported.
3) N/A
4) The surveys interviewed over 350,000 people on a daily basis (1000+ surveys per day) for
two years. Samples were selected randomly with minimum quotas for cell phone
respondents and gender. The margin of sampling error is plus or minus .2%.
5) The results are communicated clearly through a series of tables comparing happiness levels
in 2009 and 2010.