Determine Why banks raise their interest rates

A way to explain why banks raise their interest rates is as follows. With higher overnight interest rates, it is more expensive for banks to end the day with a deficit. To reduce the risk of having to borrow overnight, they can increase their reserves by increasing deposits and reducing loans, which they again accomplish by raising the interest rates.

Market interest rates are affected as well. First, when the central bank sells government securities, the price of these securities will fall and the interest rate will increase. Second, government securities are close substitutes for bank deposits, and when one of these rates changes, the other follows suit.