ORIE 6180 - The Design of Online Marketplaces

Course Description

New online marketplaces are profoundly altering our social and economic interactions. They enable unprecedented levels of monitoring and control over their participants; the complexity of their underlying functions results in the platforms and their participants interacting in intricate and subtle ways; finally, many online marketplaces are reaching scales where small design changes can have a huge impact on their performance. In this course, we will: (i) look at several important online marketplaces, and highlight their unique economic and operational challenges, and (ii) develop stochastic models that provide a principled way to reason about their operations.

  • Course Syllabus: pdf
  • Introductory lecture



  • Homeworks:
      There will be 2 homeworks, each worth 10%.
    • Homework 1 (Due at 10am on Monday, 7th March) [tex]
  • Scribing:
  • Paper Reviews:
      An important component of the class is reading and thinking about papers. To make sure of this, each student is expected to submit a mini-review for at least one paper each on pricing, search, reputation and additional topics. Each review should be less than a page, and answer the following questions:
      1. What is the problem the paper wants to solve?
      2. What are the main insights one gets from the paper?
      3. What are interesting/useful ways to extend the work?
      Each mini-review will be graded credit/no-credit, i.e., you will receive full credit for this component if you satisfactorily complete each mini-review.
    • Helpful advice on reading papers: Roughgarden, Keshav
    • Advice on reviewing: Cormode, Feamster (this is primarily for conference/journal reviews, but great advice, which should be useful both for this course, and for academic reviews in general)

Tentative Schedule

  • Unit 1: Basic tools for studying online marketplaces
    • Introduction to mechanism design and auctions
    • “Second-best” mechanism design and approximation
    • Price theory of two-sided platforms
  • Unit 2: Operational details of platform marketplaces
    • Search and visibility
    • Pricing
    • Reputation and Feedback
  • Unit 3: Additional topics (as time permits)
    • Platform competition
    • Learning with strategic agents
    • Experimentation and A/B testing in platform markets

Course Information


This course is based on a similar course taught by Ramesh Johari at Stanford: Platform and Marketplace Design.
Another great set of related courses are Tim Roughgarden's Algorithmic Game Theory and Mechanism Design.

There is no required textbook for the course; however, the following books are a great reference for various topics we'll cover. The Cornell library has access to online versions of some of these books:


Knowledge of basic probability (at the level of ORIE 6500) and optimization (at the level of ORIE 6300). Prior exposure to microeconomics and game theory would be helpful, but is not necessary.

Note though that since the course will discuss mostly active research, with reading material drawn from recent papers, the technical level required for reading the papers may vary a lot. Send a mail to the instructor if you are concerned about having the appropriate prerequisites.