MENU-SIZE COMPLEXITY AND REVENUE CONTINUITY OF BUY-MANY MECHANISMS
Yi Yifen eng Ten eng
University of Wisconsin-Madison Joint work with Shuchi Chawla and Christos Tzamos (UW-Madison)
MENU-SIZE COMPLEXITY AND REVENUE CONTINUITY OF BUY-MANY MECHANISMS - - PowerPoint PPT Presentation
MENU-SIZE COMPLEXITY AND REVENUE CONTINUITY OF BUY-MANY MECHANISMS Yi Yifen eng Ten eng University of Wisconsin-Madison Joint work with Shuchi Chawla and Christos Tzamos (UW-Madison) Buy-one mechanisms and buy-many mechanisms v(
University of Wisconsin-Madison Joint work with Shuchi Chawla and Christos Tzamos (UW-Madison)
βͺ A seller has π heterogeneous items to sell to a single buyer. βͺ Typical buy-one mechanisms: buyer interact with the seller once. βͺ Optimal strategy: purchases the third menu option, pay $999. βͺ Buy-many mechanisms: buyer interact with the mechanism multiple times. βͺ Optimal strategy: repeatedly purchase , then repeatedly purchase , pay $16 in expectation. v( )=$1000000
1 2
$5
1 3
$2 $999 v( )=v( )=$1
βͺ How many menu options are needed for (1 β π)-approx in revenue? βͺ Buy-one mechanisms: infinite [Hart Nisanβ13]. βͺ Buy-many mechanisms: finite. Theorem 1. For any distribution πΈ and π β [0,1], exists mechanism π with finite menu size π(π, π), such that πππ€πΈ π β₯ 1 β π πΆπ£π§ππππ§πππ€πΈ. Theorem 2. There exists πΈ being a distribution over XOS functions, such that for any mechanism π with description complexity 22π(π1/4), πΆπ£π§ππππ§πππ€πΈ β₯ π log π πππ€πΈ π . βͺ π π, π = 1/π 2π(π). βͺ The doubly-exponential dependency of n is tight.
βͺ When the buyerβs values for the sets of items perturb multiplicatively slightly, how much does the revenue change? βͺ Any π€ βΌ πΈ is perturbed to π€β² βΌ πΈβ², such that π€β² π β 1 β π π€(π), 1 + π π€(π) , βπ β [π]. βͺ Buy-one mechanisms: revenue may change significantly [Psomas et al.β19]. βͺ Continuity only holds for weaker additive perturbation [Rubinstein Weinbergβ15] [Brustle et al.β20]. βͺ Buy-many mechanisms: revenue changes slightly. βͺ Note: such dependency on π is necessary. βͺ Full paper: https://arxiv.org/abs/2003.10636 Theorem 3. For any value distribution πΈ and any 1 Β± π multiplicative perturbation πΈβ², πΆπ£π§ππππ§πππ€πΈβ² β₯ 1 β ππππ§ π, π πΆπ£π§ππππ§πππ€πΈ. Theorem 4. There exists πΈ over unit-demand functions and a 1 Β± π multiplicative perturbation πΈβ², such that πΆπ£π§ππππ§πππ€πΈβ² β€ 1 ππ πΆπ£π§ππππ§πππ€πΈ.