U.S. Census Bureau: Poverty

The Census Bureau's home page on poverty.  This is the source for much of the data found in the arguments both for and against the minimum wage.  As the web site makes clear, the database is vast, different methods of measuring income and poverty lead to different results, and the definitions of poverty-related terms are complex and arguable. 

Consumer Price Index

The Department of Labor's data on changes in the cost of living.

Inflationdata.com

A helpful site for accessing and understanding inflation and cost-of-living data.

Earned Income Tax Credit