Some defend lottery-ticket buying as a rational purchase of fantasy — paying a dollar for a day's worth of pleasant anticipation. But then your valuable brain is occupied with a fantasy whose real probability is nearly zero, investing emotional energy. Without the lottery, people might fantasize about things to actually do, which then might lead to making the fantasy a reality. To work around a bias, you must first notice it, analyze it, and decide that it is bad. Many people, such as the lottery advocates above, often fail to complete the third step.
Discuss the post here (rather than in the comments of the original post).
This post is part of a series rerunning Eliezer Yudkowsky's old posts so those interested can (re-)read and discuss them. The previous post was Priors as Mathematical Objects, and you can use the sequence_reruns tag or rss feed to follow the rest of the series.
Sequence reruns are a community-driven effort. You can participate by re-reading the sequence post, discussing it, posting the next day's sequence reruns post, summarizing forthcoming articles on the wiki, or creating exercises. Go here for more details, or to discuss the Sequence Reruns.