The main sources of income for public libraries typically include:

• Local Government Funding: This is the largest and most significant source, often coming from city or county general funds, property taxes, and special-purpose districts that may levy their own taxes. In the U.S., about 85-86% of public library funding comes from local taxation and government sources

• State Government Funding: State governments provide supplementary funding through direct appropriations, grants, and programs such as the Library Services and Technology Act (LSTA). However, the share from state funding has generally decreased over time, making up less than 7% of total funding in recent years

• Federal Funding: Federal contributions are usually small (around 1% or less) and often come in the form of grants for specific programs or technology improvements, such as those from the Institute of Museum and Library Services

• User Fees and Charges: Libraries generate some income through overdue fines, fees for lost or damaged items, room rentals, and charges for certain services. Although these contribute a smaller portion of income, they help supplement the budget

• Private Donations and Philanthropy: Many libraries receive gifts, donations, endowments, and grants from individuals, foundations, and corporations. Friends of the library groups and fundraising events also provide additional financial support

• Other Income Sources: These include selling old newspapers or waste materials, interest from investments, rents from vacant spaces, crowdfunding, and income from commercial activities like retail or service contracts

In summary, public libraries rely primarily on local government funding, supplemented by state and federal funds, user-generated income, and private donations to sustain their operations and services. The exact mix varies by location and library governance structure