Great Depression Giving - Where's the data?

The Economist is just the latest source to run a line about giving that goes something like this:

"During the Great Depression, giving rose. Over the past 40 years there have been several recessions, but just one year in which total giving has fallen in America: 1987, the year of the “Black Monday” stockmarket crash."

Here's what I want to know - what data show that giving rose during the Great Depression (1929-1942)? It certainly wasn't whatever data source is referenced in the second sentence above, since 'the past 40 years' takes us back to 1968. My sense is that the '40 year' data come from some combination of Giving USA, AAFRC, IUPUI, Foundation Center, and possibly IRS returns.*

But what is the source for the assertion that giving rose during the Great Depression? The Foundation Center didn't exist then (Founded in 1956). Giving USA goes back 50+ years, which still doesn't get us into the 1930s. Is there research, tax data, trend analysis - what is the source or sources for this claim? If you know, please let me know. Thanks.


*Of course, it would be nice if there were actually citations provided for this 40 year trend, but now I've gone and gotten all academic on you.

Tags: philanthropy, giving, trends, economist, givingusa, foundationcenter