SOUTHWEST AIRLINES CO

16. SUPPLEMENTAL FINANCIAL INFORMATION

(a) As of December 31, 2022, included customer reimbursement expenses due to the Company's December 2022 operational disruption and refund submissions that had yet to be processed. As of December 31, 2023, amounts primarily consist of normal current activity.

(b) Primarily consists of anticipated contract labor ratification bonuses and/or accruals. Also includes non-contract incentive pay. Included in Salaries, wages and benefits expense for the year ended December 31, 2023, are incremental expenses of $180 million for changes in estimate related to the contract ratification bonus for the Company’s Flight Attendants, and $354 million related to the contract ratification bonus for the Company's Pilots. The cumulative $534 million is included in the balance as of December 31, 2023. The Company began accruing for these open labor contracts on April 1, 2022. The incremental $180 million expense related to the contract ratification bonuses for Flight Attendants extends the timeframe covered by the ratification bonus to the date the contract became amendable on November 1, 2018. The incremental $354 million expense related to the contract ratification bonuses for Pilots is primarily to increase pay rates for all periods to the date the contract became amendable, which was September 1, 2020. These bonuses for both Flight Attendants and Pilots serve to compensate for missed wage increases over these time periods.

(c) The purpose of Voluntary Separation Program and Extended ETO was to maintain a reduced workforce to operate at reduced capacity relative to the Company's operations prior to the COVID-19 pandemic. In accordance with the accounting guidance in Accounting Standards Codification Topic 712 (Compensation — Nonretirement Postemployment Benefits), the Company accrued charges related to the special termination benefits described above upon Employees accepting Voluntary Separation Program or Extended ETO offers. The Company accrued expenses totaling $1.4 billion for its Voluntary Separation Program and Extended ETO program in 2020, which are being reduced as program benefits are paid. For both the Voluntary Separation Program and Extended ETO programs combined, approximately $93 million and $109 million of the liability balances were relieved during 2023 and 2022, respectively, through payments to Employees. During 2021, the Company determined that it was no longer probable that the remaining portion of the Employees on Extended ETO would remain on such leave for their entire elected term. Therefore, a portion of the accruals previously recorded were reversed, resulting in a net $140 million credit to expense during 2021, and the entire liability was fully relieved at March 31, 2022. Both the initial charge and the partial reversal were classified within Payroll support and voluntary Employee programs, net, in the accompanying Consolidated Statement of Income, and are in addition to the allocation of the PSP2 Payroll Support Program and PSP3 Payroll Support Program funds utilized to fund salaries, wages, and benefits, which totaled $2.7 billion for the year ended December 31, 2021.

For further information on fuel derivative and interest rate derivative contracts, see Note 11.

Other Operating Expenses

Other operating expenses consist of aircraft rentals, distribution costs, advertising expenses, personnel expenses, professional fees, and other operating costs, none of which individually exceed 10 percent of Total operating expenses, net.