Prepaid Expenses and Other Assets. Prepaid expenses and other assets increased $132,000, or 85.2%, to $287,000 at September 30, 2020 from $155,000 at December 31, 2019. The increase resulted principally from an increases of $62,000 in prepaid income taxes, $35,000 in fees receivable on loans sold and $35,000 in prepaid expenses.
Deposits. Deposits decreased $2.5 million, or 4.3%, to $55.6 million at September 30, 2020 from $58.0 million at December 31, 2019, principally due to a $2.6 million decrease in certificates of deposit, or 4.7%, to $52.7 million at September 30, 2020 from $55.2 million at December 31, 2019. The decrease in certificates of deposit resulted primarily from a decreases of $5.6 million in certificates of deposit from municipalities and $496,000 of local retail certificates of deposit, offset in part by an increase in certificates of deposit derived from an online service of $3.5 million. We have sometimes utilized the non-retail funding sources to fund our loan origination and growth and to replace Federal Home Loan Bank advances.
Borrowings. Borrowings, consisting entirely of Federal Home Loan Bank (FHLB) advances, increased $185,000, or 0.9% to $21.8 million at September 30, 2020 from $21.6 million at December 31, 2019, as we secured $4.0 million of new advances to replace $3.8 million of maturing advances to take advantage of historically low 5-year advances to help manage interest rate risk.
Total Equity. Total equity decreased $1.1 million, or 4.6%, to $23.2 million at September 30, 2020 from $24.3 million at December 31, 2019. The decrease resulted primarily from the repurchase of $1.1 million of shares of common stock and the net loss of $111,000 during the nine months ended September 30, 2020, offset in part by an increase in accumulated other comprehensive income of $67,000 and a decrease of $35,000 in unallocated common stock held by our ESOP.
Comparison of Operating Results for the Three Months Ended September 30, 2020 and 2019
General. We had a net loss of $68,000 for the three months ended September 30, 2020, compared to net income of $53,000 for the three months ended September 30, 2019, a decrease of $121,000. The decrease in net income resulted from decreases in net interest income of $191,000 and noninterest income of $16,000, offset, in part, by decreases in noninterest expense of $78,000 and income tax expense of $8,000.
Interest Income. Interest income decreased $309,000, or 31.6%, to $670,000 for the three months ended September 30, 2020 from $979,000 for the three months ended September 30, 2019. This decrease was attributable to decreases in interest on loans receivable of $220,000, interest on investment securities of $31,000 and interest on other interest-earning assets of $58,000. The average balance of loans decreased $10.5 million, or 12.9%, to $70.5 million for the three months ended September 30, 2020 from $81.0 million for the three months ended September 30, 2019, and the average yield on loans decreased 61 basis points to 3.66% for the three months ended September 30, 2020 from 4.27% for the three months ended September 30, 2019. The average balance of investment securities decreased $2.6 million, or 37.0%, to $4.5 million for the three months ended September 30, 2020 from $7.1 million for the three months ended September 30, 2019, while the average yield on investment securities decreased 127 basis points to 1.25% for the three months ended September 30, 2020 from 2.52% for the three months ended September 30, 2019. The average balance of other interest-earning assets increased $7.5 million, or 55.8%, to $20.8 million for the three months ended September 30, 2020 from $13.4 million for the three months ended September 30, 2019, and the average yield on other interest-earning assets decreased 185 basis points to 0.21% for the three months ended September 30, 2020 from 2.06% for the three months ended September 30, 2019.
Interest Expense. Total interest expense decreased $118,000, or 23.6%, to $382,000 for the three months ended September 30, 2020 from $500,000 for the three months ended September 30, 2019. The decrease was due to decreases of $93,000, or 27.9% in interest expense on deposits and $25,000, or 15.0%, in interest expense on advances from the FHLB. The average balance of interest-bearing deposits in banks decreased $7.2 million, or 11.5%, to $55.7 million for the three months ended September 30, 2020 from $63.0 million for the three months ended September 30, 2019, and the average cost of interest-bearing deposits in banks decreased 39 basis points to 1.72% for the three months ended September 30, 2020 from 2.11% for the three months ended September 30, 2019. The average balance of FHLB advances decreased $865,000, or 3.7%, to $22.2 million for the three months ended September 30, 2020 from $23.1