Just to follow up, I checked the cans, and both the Italian and US brands say "total dietary fiber" or "dietary fiber"; they don't distinguish between soluble and insoluble fiber.
I wondered if maybe the smaller the bean, the more the fiber (i.e., greater surface-area-to-volume-ratio; what can I say, I'm a geek), but neither the cans in my pantry nor the websites I googled supported this hypothesis. So I take that to mean the fiber's not necessarily primarily in the skin of the bean.
My research continues. There's a long, cold, Chicago winter coming and I have a lot of canned goods to help me through it. I'll report back.
"Your swimming suit matches your eyes, you hold your nose before diving, loving you has made me bananas!"