Net interest income is a key measure for banks as it provides a direct measure of the interest income generated on loans after the deducting of the interest expense incurred in issuing credit. It is also a reliable indicator of how successful a bank is in funding its assets with debt, as well as collecting payment for loans it has made. Banks monitor their net interest income to ensure they are making enough income on their loans and that interest rates on their loans and deposits remain competitive.

To increase their net interest income, banks often focus on collecting payments on time, maximizing the amount of interest they can charge on loans, and taking greater and more profitable risks in their loan portfolios. Banks may also reduce the interest they pay to their depositors and increase the amount they charge on their loans.

Changes in interest rates have a significant impact on a bank's net interest income. When interest rates fall, the interest earned on a bank's assets will decrease, while its interest expenses remain the same or at least a little less. This means the bank will be collecting less money in interest on its assets and paying the same or less on its liabilities, resulting in a lower net interest income.

Similarly, when interest rates rise, the bank will collect more income from its assets, while its liabilities will remain the same or only increase slightly. This will increase the bank's net interest income. Net interest income is an important measure of the profitability of a bank and its ability to remain competitive. Without a healthy amount of net interest income, a bank may struggle to stay afloat. As such, banks aggressively monitor and manage their net interest income to ensure they remain profitable.