The US Federal Reserve Bank System publishes details of the nation's economic conditions as Beige Books. Published 8 times a year, Beige Books gather information on current economic conditions through reports from Bank and Branch directors and interviews with key business contacts, economists, market experts, and other sources. They are an important source of recent information since many of the other key regional economic statistics such as personal income and gross state product, are only released after a significant lag. Beige Books provide powerful data on how the economy is doing at a grassroots level.