Every indexed document

beyond what we would actually get rewarded for.

or perhaps motivating us to devote too much of our

perhaps motivating us to ensure that others solve it

we would be sensitive to whether the problem

provided others recognize it as a problem and

then we would be happier if there were fewer afflicted

since the donor will be motivated to uncover efficacy herself.

this is perhaps more important than informing the donor

and we ourselves will not attend to effectiveness in equilibrium. This

they donated identical amounts (Karlan & List

when donors are told their donations will be matched

” despite the fact that our likelihood of swinging

we will argue that these features might be puzzling

but they do not know that others know this

it must be the case that others can tell that a player had

contributions need to be observed with sufficiently high

players play a Repeated Prisoner’s Dilemma (see

there is ample evidence for the Repeated

provided δ > c /b . In all such equilibria

there are equilibria in which players end