Why do revenue bonds carry higher interest rates than general obligation bonds?

1. Municipal bonds are issued by states, cities, counties and other state and local government agencies, typically with a par value of $5,000. 2. They come as either general obligation bonds or revenue bonds. 3. General obligation bonds are backed by the full faith and credit, and the taxing power, of the issuing government. 4. Revenue bonds are repaid only from income generated by the specific project being financed, such as a toll highway, a power plant or a parking structure. 5. The issuer has no legal obligation to back a revenue bond if the project's revenues fall short. 6. That makes revenue bonds more risky, so they must offer higher interest rates to attract buyers. _Source: OpenStax Introduction to Business (CC BY 4.0), Ch 16 "Understanding Financial Management and Securities Markets", section 16.6 Securities Markets_