I don't have the expertise to comment on the economic aspects of the 'gift economy', and its potential dangers to GDPs, but I would like to bring up an aspect that I've not seen mentioned here, yet: aesthetics.

I live in an abode that's furnished primarily with stuff I've found on the streets of Paris, not so much out of need but because I enjoy the idea that these objects have had a previous life. I look at the 30s-style fauteuil [probably discarded hotel furniture] I recuperated and renovated, and think of the variety of bums it must have known: criminals, lovers, tourists...

In a sense, my home is full of past, perhaps unresolved, mysteries and stories, no doubt some of them beautiful, others less so. Y'know, real, life-like matters.

Ikea doesn't give you that. :-)