The study looked at how having more money in the bank's own funds can make it cheaper for the bank to borrow money. They studied banks from many countries between 1991 and 2017. They found that banks with more of their own money had lower borrowing costs. Investors like it when banks have more of their own money, especially pure equity. Other types of money, like Tier 2 capital, are not as valuable to investors. This finding was true for banks in both rich and poor countries. The study shows that having more of their own money can help banks save money when they need to borrow.