Oxfam diversifies its collection methods

Last evening I answered a knock at my door to find two young men standing there.

"Hi mate", said the one with the clipboard "have you heard of Oxfam?" I replied that not only had I heard of it but that I was a donor. End of discussion.

I wondered whether they were, despite their displaying what looked like Oxfam ID, genuine, so this morning I rang the Oxfam state office. I was told that Oxfam had engaged a contractor to collect door to door. I wonder how much of each dollar collected in this manner actually reaches Oxfam. In fact I wonder how much of each dollar that I donate to them actually reaches projects in the field...