Quote from: casascius on October 21, 2012, 07:00:01 PM

If the main decision that the user had to make was a) how much disk space am I willing to contribute to bitcoin [knowing it can be reclaimed anytime if needed], and b) how much bandwidth do I want to contribute, then we could probably get users to make the right decision every time without burdening them with the details.

That generally results in "what am I getting out of this? Uh. I don't care. It works with zero right? Zero." I'd rather express bandwidth settings in terms of rate limiters. Setting yourself down would reduce your contribution, but would also reduce your consumption. Setting it high makes you contribute more but also makes your Bitcoin update faster. So even someone with a very simple understanding of the option knows that he's getting something out of cranking it up. we have this with listening today, without listening you "only" get three bars. To get your >8 connections and four bars you must listen. And people do go out of their way to setup the port forwards just to make the gauges go up not because they're trying to help the network, but because they expect it will make it work better.

The idealized rational participant realizes that running a full node is both good for their own security and that it's good for their financial interests because it's good for the network. But knowledge isn't frictionless and recognition of the rational choice requires some somewhat subtle thought. Humans tend to reason poorly about the risks of unlikely events (e.g. someone performing a technical attack against thin clients), they only tend to care _after_ everyone has been ripped off. We already see this directly where people are using thin clients (not even SPV) and web wallets and believing it to be just as secure, or modifying their client to make 800 outbound connections and not being _at all_ concerned about the burden they're placing on the network or realizing the doing so is harmful to their own interests in any case.

Bitcoin is secure against attack when the honest participants are rational and selfish. But if many of the participants are _irrational_ and selfish then they need to be offset by altruistic participants who contribute more resources. Education can help, but there are limits because the lack of time or interest that creates the irrational behavior also keeps education from being effective. As far as I can tell the way to maximize altruism is to make it the default so that everyone who is indifferent is altruistic but leave it possible to tone it down if it turns out to be problematic, so that people aren't forced to completely eliminate their contribution if its too burdensome.