27 research outputs found
Computing large market equilibria using abstractions
Computing market equilibria is an important practical problem for market
design (e.g. fair division, item allocation). However, computing equilibria
requires large amounts of information (e.g. all valuations for all buyers for
all items) and compute power. We consider ameliorating these issues by applying
a method used for solving complex games: constructing a coarsened abstraction
of a given market, solving for the equilibrium in the abstraction, and lifting
the prices and allocations back to the original market. We show how to bound
important quantities such as regret, envy, Nash social welfare, Pareto
optimality, and maximin share when the abstracted prices and allocations are
used in place of the real equilibrium. We then study two abstraction methods of
interest for practitioners: 1) filling in unknown valuations using techniques
from matrix completion, 2) reducing the problem size by aggregating groups of
buyers/items into smaller numbers of representative buyers/items and solving
for equilibrium in this coarsened market. We find that in real data
allocations/prices that are relatively close to equilibria can be computed from
even very coarse abstractions
Pacing Equilibrium in First-Price Auction Markets
In the isolated auction of a single item, second price often dominates first
price in properties of theoretical interest. But, single items are rarely sold
in true isolation, so considering the broader context is critical when adopting
a pricing strategy. In this paper, we study a model centrally relevant to
Internet advertising and show that when items (ad impressions) are individually
auctioned within the context of a larger system that is managing budgets,
theory offers surprising endorsement for using a first price auction to sell
each individual item. In particular, first price auctions offer theoretical
guarantees of equilibrium uniqueness, monotonicity, and other desirable
properties, as well as efficient computability as the solution to the
well-studied Eisenberg-Gale convex program. We also use simulations to
demonstrate that a bidder's incentive to deviate vanishes in thick markets
Performance evaluation methods for the the trading agent competition
This paper proposes a novel method to characterize the performance of autonomous agents in the Trading Agent Competition for Supply Chain Management (TAC-SCM). We create benchmarking tools that manipulate market environments to control the conditions and provide guidelines to test trading agents. Using these tools, we show how developers can inspect their agents and unveil behaviors that might otherwise have gone undiscovered
A Predictive Model for Advertiser Value-Per-Click in Sponsored Search
Sponsored search is a form of online advertising where advertisers bid for placement next to search engine results fo