Online machine learning for bilateral trading problems
Άμεση μηχανική μάθηση για προβλήματα διμερών συναλλαγών
Master Thesis
Author
Αγγελοπούλου, Ειρήνη
Angelopoulou, Eirini
Date
2022Advisor
Τελέλης, ΟρέστηςTelelis, Orestis
View/ Open
Keywords
Online learning ; Online auctions ; Machine learning ; Predicting from expert advice ; Multiarmed bandit problemAbstract
In this work, we are studying Online Learning and its application in Online Auctions
through intermediation. These days, all transactions on modern platforms are conducted
exclusively through real-time online auctions. The design of such auctions and their properties
have initiated a lot of research in the past years, focusing on designing the optimal auction
mechanism to maximize the seller’s revenue.
Specifically, throughout this study, we explore bibliographically the Online Learning and
its key ideas and methods. We begin with the Full Feedback and the Expert Advice methods,
followed by the Partial Feedback and the Bandit general setting. Afterwards we continue our
investigation with the problem of Online Auctions and the Double Auction or Bilateral Trade
setting, which we will also examine in the experimental section too.
For the experiment, we explore the algorithms we presented in the section on Online
Learning. Initially, we selected three Full-feedback algorithms, the Follow the Best
Price algorithm, a modified Follow the Best Price with Greedy sampling, and the Exponential
Weighted Average algorithm. We then continued the analysis with an ε-Greedy algorithm from
the Partial-feedback category of algorithms.
We compare the performance of the above algorithms in the Bilateral Trade setup,
selecting four different sets for the sellers’ and the buyers’ prices. All the algorithms tested
achieved small (logarithmic) regret and generally the findings verify the theoretical results.
Comparing the results of the algorithms, the Follow the best price algorithm is the best
performing algorithm for most of the sets while the ε-Greedy algorithm is the worst. Our
modified Follow the Best Price with Greedy sample algorithm achieved the best results, actually
outperforming the original Follow the Best Price algorithm, in one of the four experiments.