Learning to Clear the Market International Conference on Machine - - PowerPoint PPT Presentation

learning to clear the market
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Learning to Clear the Market International Conference on Machine - - PowerPoint PPT Presentation

Learning to Clear the Market International Conference on Machine Learning (ICML) June 11, 2019 Weiran Shen, Tsinghua University Sbastien Lahaie, Google Research Renato Paes Leme, Google Research Reserve Pricing Bidders: $1, $2, $4, $5


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SLIDE 1

Learning to Clear the Market

Weiran Shen, Tsinghua University Sébastien Lahaie, Google Research Renato Paes Leme, Google Research

International Conference on Machine Learning (ICML) June 11, 2019

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SLIDE 2

Bidders: $1, $2, $4, $5

  • nonconvex, discontinuous

[Medina-Mohri, 2014]

  • gradient often zero
  • ptimal reserve is aggressive:

high probability that the item is unsold

Reserve Pricing

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In a display ad auction:

  • Supply = 1 single impression
  • Want: Demand = 1 single bidder
  • Set price between first- and second-highest bids.

Market-Clearing Price

$4 $2 $1 $5

clearing prices {

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SLIDE 4

Formulate the (trivial) efficient allocation problem as an LP:

maxx ≥ 0 ∑i bi xi s.t. ∑i xi = λ

Default choice is λ = 1. The dual of the allocation problem is a pricing problem:

minp ∑i max{bi - p, 0} + λ p

Artificially increasing or limiting supply via λ controls how conservative or aggressive the resulting prices are.

Deriving the Loss Function

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SLIDE 5

Bidders: $1, $2, $4, $5

  • piecewise linear, convex
  • robust to outliers
  • all bids shape the loss

Market Clearing Loss

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SLIDE 6

Revenue vs. Match Rate Trade-off

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SLIDE 7
  • Loss that captures the “market value” of an item (e.g., an ad impression).
  • Allows fine-grained control of the revenue vs. match rate trade-off.
  • Outperforms regression and surrogate loss benchmarks in terms of

trade-offs and convergence rates.

Summary More details at Poster #156.