It would be great to add a link to the article on charitable giving you refer too to see if they already conclude or dismiss my idea on the issue. From observations of those around me I tend to see the reason behind charitable giving as something other than maximizing the utility of the charitable gift. I postulate that people give to many different charities as a social signal. The contributor is signaling to those who are receiving the gift that they sympathize with the cause. The contributor is also signaling to those around them that they are a caring and compassionate person. The quantity of the gift has an almost negligible effect on this signaling. So the more times someone gives, and the more charities they give too allows them to signal positive social mores more often and to a larger audience, increasing their social status higher, than if they gave all their expendable money to one charity a limited number of times.
The true cost of acting rational is the difference between acting truly rational versus acting purely rational in a situation.
First we have to make the distinction between what is factual truth or strategically optimal and what an agent believes is true or strategically optimal. For non-rational agents these are different, there is at least one instance where what they believe is not what is true or how they act is not optimal. For rationalists, what they believe has to be proven true and they must act optimally.
A situation with only rational agents, they would find the optimal cumulative payoff and distribute it optimally in-line with potentially different goals. This assumes rational agents can agree on an optimal distribution strategy, possibly based on incurred costs (time, resources spent) and goal priority, and have non-conflicting goals.
Non-rational agents may have conflicting goals, be greedy and not achieve optimal distribution, and may not find or implement the strategy to achieve the best cumulative payoff. Each of these areas identifies costs of non-rationality.
In a situation in which rationalist agents must work with non-rationalist agents there will be a cost of non-rationality no matter how the rationalist acts. In these situations a pure rationalist will act differently than a true rationalist. Truly rational agents take into account both factual truth and non-rational agents beliefs and strategies when deciding strategy. The true rationalists will pursue strategies that achieve a sub-optimal but minimum cost. Purely rational agents only take into account factual truth when deciding strategy and does not account for non-rational agents beliefs or strategies. Pure rationalists will incur costs above this sub-optimal minimum. Thus, the true cost of acting rational is the difference between the cost of acting purely rational and acting truly rational.
lava, You aren't the only one on LW that feels the same way. I have similar background and concerns. We are not outsiders. LW's dedication to attacking the reasoning of a post/comment, but not the person has been proved over and over.