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| author | Stratis Ioannidis <stratis@stratis-Latitude-E6320.(none)> | 2013-07-06 17:15:37 -0700 |
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| committer | Stratis Ioannidis <stratis@stratis-Latitude-E6320.(none)> | 2013-07-06 17:15:37 -0700 |
| commit | 4a89391c9d18d8a2e1b3a88bc3bf108890e2cad1 (patch) | |
| tree | c71429ac8954e140980f4e82298566b411a07b68 /problem.tex | |
| parent | 29312afd055f4bc56887cc417dca889faf101170 (diff) | |
| download | recommendation-4a89391c9d18d8a2e1b3a88bc3bf108890e2cad1.tar.gz | |
payoff
Diffstat (limited to 'problem.tex')
| -rw-r--r-- | problem.tex | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/problem.tex b/problem.tex index 6c717af..f3ac078 100644 --- a/problem.tex +++ b/problem.tex @@ -148,7 +148,7 @@ $S:\reals_+^n \to 2^\mathcal{N}$, determining the set $p:\reals_+^n\to \reals_+^n$, determining the payments $[p_i(c)]_{i\in \mathcal{N}}$ received by experiment subjects. We seek mechanisms that are \emph{normalized} (unallocated experiments receive zero payments), \emph{individually rational} (payments for allocated experiments exceed costs), have \emph{no positive transfers} (payments are non-negative), and are \emph{budget feasible} (the sum of payments does not exceed the budget $B$). -We relax the notion of truthfulness to \emph{$\delta$-truthfulness}, requiring that reporting one's true cost is an \emph{almost-dominant} strategy: no subject increases their payoff by reporting a cost that differs more than $\delta$ from their true cost. Under this definition, a mechanism is truthful if $\delta=0$. +We relax the notion of truthfulness to \emph{$\delta$-truthfulness}, requiring that reporting one's true cost is an \emph{almost-dominant} strategy: no subject increases their utility by reporting a cost that differs more than $\delta$ from their true cost. Under this definition, a mechanism is truthful if $\delta=0$. In addition, we would like the allocation $S(c)$ to be of maximal value; however, $\delta$-truthfulness, as well as the hardness of \EDP{}, preclude achieving this goal. Hence, we seek mechanisms with that yield a \emph{constant approximation ratio}, \emph{i.e.}, there exists $\alpha\geq 1$ s.t.~$OPT \leq \alpha V(S(c))$, and are \emph{computationally efficient}, in that the allocation and payment functions can be computed in polynomial time. We note that the $\max$ operator in the greedy algorithm \eqref{eq:max-algorithm} breaks |
