Looking for a Bargain(ing) at Auction

Daniel
Hermosillo
Alistair
Wilson
Behavioral Brownbag
October 2025

Competitive bidding with a possibility of being the only competitor

Motivating Idea

  • We call a contractor to come perform a renovation in our home:
    • They provide a bid on the job 
    • We give them the job or not
  • Does the bid given depend on how nice our house is?! 

Motivating Idea

Well, it depends...

  • If we called multiple contractors would typically model this as an auction
    • Bids do not depend on the homeowners reservation
  • If there's any chance we only called one contractor then bids will depend on homewner's reservation value

Model

\(\Longrightarrow\)

Nature

\(\mathcal{N}=\left\{1\right\}\)

\(\mathcal{N}=\left\{1,2\right\}\)

\(p\)

\(1-p\)

Each bidder:

  • Draws cost \(c_i\in[\underline{c},\overline{c}]\)
  • Chooses bid \(\beta(c)\)
  • Contract awarded to lowest bidder
    • so long as bid below reservation \(\omega>\overline{c}\)

Notation

  • \(p\)  - Probability only one bidder
  • \(\omega\) - Reservation price for auction
  • \(c\) -  Agent's cost to provide the service
  • \(\beta(c)\) - The equilibrium bid function
  • \(\left[\underline{c},\overline{c}\right]\) - The support for bids

Model

Symmetric theoretical solution :

  • Assume bid function \(\beta(c)\) is strictly increasing
  • Bidders expected profit is given by:\[\pi(b|c)=\Pr\left\{b\text { lowest bid}\left|\beta\right.\right\}\cdot (b-c)\]

Model

First-order condition leads to a differential equation:

\[\frac{\beta(c)-c}{\overline{c}-\underline{c}}=\beta^\prime (c)\frac{\Pr\left\{\text{Lowest }c\right\} }{ \Pr\left\{\text{Not alone} \right\} }\]

  • To solve this we need a boundary condition on the highest cost type:
    • With \(p=0\) this is \(\beta(\overline{c})=\overline{c}\)
    • With \(p>0\) this is \(\beta(\overline{c})=\omega\)

Stylized Data

  • Look at all permits in Allegheny Count
  • Focus on electrical panel installations
    • Common residential upgrade
    • Minimize unobserved heterogeneity
    • Lists size of the panel in Amperes
  • Have 2,196 permit applications

Stylized Data

  • Regress permit project value \(\log(\$V)\) on
Variable Coefficient p-Val.
Intercept (100A panel in 2020) $1260 <0.001
per 100A 36% <0.001
z(Census income) 5% <0.001
per year increase 5.6% <0.001

Stylized Data

Design Sketch

Costs drawn from \(U[\$500,\$1500]\) with \(2\times 2\) design over:

  1. Reservation of
    • Low: \(\omega=\$2,500\)
    • High: \(\omega=\$3,500\)
  2. Uncertainty over #bidders
    • Scenario 1: \( \tfrac{3}{4}\cdot 2\text{ bidders} \oplus \tfrac{1}{4}\cdot 1\text{ bidder}\)
    • Scenario 2: \( \tfrac{3}{4}\cdot 2\text{ bidders} \oplus \tfrac{1}{4}\cdot 3\text{ bidders}\)

Design Sketch

Design Sketch

Design Sketch

Theory Hypotheses

  1. No response to reservation if \(\Pr(N=1)=0\)
  2. Response to reservation if \(\Pr(N=1)>0\)
    1. Reservation pricing only by the highest cost type
    2. Higher conditional markups for higher cost types

Behavioral Hypotheses

  1. Response to reservation even when \(\Pr(N=1)=0\)
  2. Pooling on reservation by many cost types

Questions

  • Is this interesting?
    • Auction research can be dull
  • Are there elements missing?
    • Robot/Human homeowner
  • Additional elements:
    • Contractor survey
    • Homeowner survey
    • Cleaning data

Thank You!

🙏

BargainAuction

By Alistair Wilson

BargainAuction

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