Introduction

Abstract

The practice of business is changing. More and more companies are amassing larger and larger amounts of data, storing them in bigger and bigger databases. Every day, telephone companies are collecting several terabytes of data about who we call, when we call them, and how long we talk to them. Every time we scan our loyalty card at a grocery store, we provide valuable information about the products we like, when we consume them, and the price we are willing to pay for them. In fact, data collection has become particularly valuable for understanding the relationship between price and demand. Large Consumer-to-Consumer (C2C) online auction sites (such as eBay or uBid) own immense treasure chests of price and demand data as they observe individuals’ willingness to pay (i.e., individuals’ bids) as well as product supply (i.e., auction inventories) and demand (i.e., the proportion of auctions that transact), dispersed both geographically (i.e., across different markets and nations) and temporally (i.e., across economically or seasonally changing environments).