Published by Council for Community and Economic Research (C2ER) since 1968, the Cost of Living Index (COLI) is the premier source of data on living cost differentials among U.S. urban areas. In contrast to other indexes using "black box" calculations, the data and methodology for the COLI are completely transparent to users. Data from the Cost of Living Index is recognized by the U.S. Census Bureau, US Bureau of Labor Statistics, and the President's Council of Economic Advisors. The Index is also included in the federal government's annual Statistical Abstract of the United States.
The COLI compares differences in the cost of living for professional households from the top 20% of income earners. It calculates an urban area's relative cost of living in comparison to the national average in a composite index and across six components indices: groceries, housing, utilities, transportation, healthcare, and miscellaneous goods and services. Since 2013, the Center for Business and Policy Research (CBPR) has collected quarterly COLI price data on nearly 60 different goods and services for San Joaquin County cities. In 2015 the CBPR expanded its work in this area to cover the City of Sacramento. That data is submitted to C2ER where it is compiled along with data from hundreds of other partner organizations across the United States. The COLI thereby provides uniquely accurate and comparable national cost of living data on San Joaquin County's four largest urban areas as well as the City of Sacramento. Thus, the data is valuable for economic development and local planning.