30, 2020, $0.8 million and $1.7 million, respectively, is included within Cost of services and $4.4 million and $14.0 million, respectively, is included within Selling, general, and administrative in the Condensed Consolidated Statements of Income. For the three and six months ended June 30, 2019, we incurred $7.4 million of expenses related to this plan which is included within Selling, general, and administrative. Refer to Part I, Item 1, Financial Statements, Note 5, Restructuring-Related Expenses for further discussion.
These expenses are specific to this initiative; however, the types of expenses related to this initiative are similar to expenses that we have previously incurred and can reasonably be expected to incur in the future.
Cost of Services
Cost of services primarily consists of agent commissions, which represented approximately 60% of total cost of services for both the three and six months ended June 30, 2020. Cost of services decreased for the three and six months ended June 30, 2020 compared to the corresponding period in the prior year due to a decrease in agent commissions in our Consumer-to-Consumer money transfer business, which generally vary with revenues, including due to fluctuations in the exchange rate between the United States dollar and foreign currencies, the Speedpay divestiture during the second quarter of 2019, and a decrease in employee-related expense, including as a result of reduced hiring, partially offset by an increase in credit losses.
Selling, General, and Administrative
Selling, general, and administrative expenses decreased for the three and six months ended June 30, 2020 compared to the corresponding period in the prior year due to decreases in employee-related expenses, including incentive compensation and as a result of reduced hiring and savings from our restructuring plan. In addition, selling, general, and administrative expenses benefited from decreases in marketing costs and costs related to strategic initiatives, including for the review and closing of mergers, acquisitions, and divestitures. For the six months ended June 30, 2020, these decreases were partially offset by the impacts of the strengthening of the United States dollar against foreign currencies.
Total Other Income/Expense, Net
Total other income/expense, net during the three and six months ended June 30, 2019 was impacted by the non-recurring gain on the sale of our United States based electronic bill payments business, known as Speedpay. In addition, total other income/expense, net during the three and six months ended June 30, 2020 compared to the corresponding periods benefited from a reduction in interest expense driven by a lower weighted-average interest rate on our outstanding debt.
Income Taxes
Our provision for income taxes for the three and six months ended June 30, 2020 and 2019 is based on the estimated annual effective tax rate, in addition to discrete items. Our effective tax rates on pre-tax income were 16.2% and 17.5% for the three months ended June 30, 2020 and 2019, respectively, and 14.3% and 18.1% for the six months ended June 30, 2020 and 2019, respectively. The decrease in our effective tax rate for the three months ended June 30, 2020 compared to the prior period was primarily due to an increase in prior period domestic pre-tax income due to the sales of the Speedpay and Paymap businesses, partially offset by increased discrete expenses in the current period. The decrease in our effective tax rate for the six months ended June 30, 2020 compared to the prior period was primarily due to an increase in prior period domestic pre-tax income due to the net gain on the sales of Speedpay and Paymap.
We have established contingency reserves for a variety of material, known tax exposures. As of June 30, 2020, the total amount of tax contingency reserves was $308.2 million, including accrued interest and penalties, net of related items. Our tax reserves reflect our judgment as to the resolution of the issues involved if subject to judicial review or other settlement. While we believe that our reserves are adequate to cover reasonably expected tax risks, there can be no assurance that, in all instances, an issue raised by a tax authority will be resolved at a financial cost that does not exceed our related reserve. With respect to these reserves, our income tax expense would include: (i) any changes in tax reserves arising from material changes in facts and circumstances (i.e., new information) surrounding a tax issue during the period,