The following table summarizes other income (expense), net for the years ended December 31, 2021, 2020 and 2019 (in thousands):


	Year Ended December 31,
	2021		2020		2019
Interest income	$	5,116	$	6,351	$	7,744
Interest expense	(17,206)		(33,192)		(23,593)
Changes in fair value of investments	95,623		(8,089)		(31,061)
Loss on extinguishment of debt	(5,090)		—		—
Foreign currency gains (losses), net and other (1)	14,237		17,962		(6,419)
Other income (expense), net	$	92,680	$	(16,968)	$	(53,329)

(1)Includes a $32.3 million cumulative foreign currency translation adjustment gain that was reclassified into earnings during the first quarter of 2021 as a result of the substantial liquidation of our subsidiary in Japan as part of our restructuring actions. See Note 14, Restructuring and Related Charges, for additional information.

The following table summarizes prepaid expenses and other current assets as of December 31, 2021 and 2020 (in thousands):


	December 31,
	2021		2020
Prepaid expenses	$	28,550	$	18,038
Income taxes receivable	7,711		5,437
Deferred cloud implementation cost	6,476		4,942
Other	9,833		12,024
Total prepaid expenses and other current assets	$	52,570	$	40,441

The following table summarizes other non-current assets as of December 31, 2021 and 2020 (in thousands):


	December 31,
	2021		2020
Debt issue costs, net	660		1,852
Deferred contract acquisition costs	7,080		5,315
Deferred cloud implementation costs (1)	11,986		10,402
Other	5,376		5,165
Total other non-current assets	$	25,102	$	22,734

(1)Following our review of long-lived assets for impairment in the first quarter of 2020, as described in Note 3, COVID-19 Pandemic, we recognized $0.9 million of long-lived asset impairments related to our EMEA operations, which is included in Other non-current assets.

The following table summarizes accrued merchant and supplier payables as of December 31, 2021 and 2020 (in thousands):


	December 31,
	2021		2020
Accrued merchant payables	$	258,101	$	303,260
Accrued supplier payables (1)	11,408		107,703
Total accrued merchant and supplier payables	$	269,509	$	410,963

(1)Amounts include payables to suppliers of inventories and providers of shipping and fulfillment services.

The following table summarizes accrued expenses and other current liabilities as of December 31, 2021 and 2020 (in thousands):


	December 31,
	2021		2020
Refund reserve (1)	$	19,601	$	33,173
Compensation and benefits	30,367		54,958
Accrued marketing	37,900		15,299
Restructuring-related liabilities	11,349		13,746
Customer credits	56,558		61,006
Income taxes payable	601		7,862
Deferred revenue	3,523		11,223
Operating and finance lease obligations	32,663		37,755
Deferred cloud computing contract incentive	3,000		3,000
Other (2)	43,751		56,977
Total accrued expenses and other current liabilities	$	239,313	$	294,999

(1)In 2020, we experienced increased refund levels due to the impacts of COVID-19 which impacted our refund reserve estimate.

(2)Includes $2.7 million as of December 31, 2021 and $2.9 million as of December 31, 2020 in certain payroll taxes under the Coronavirus Aid, Relief and Economic Security ("CARES") Act. The 2020 balance was paid in the fourth quarter 2021. The 2021 balance is due by December 31, 2022.

The following table summarizes other non-current liabilities as of December 31, 2021 and 2020 (in thousands):


	December 31,
	2021		2020
Contingent income tax liabilities	$	24,213	$	25,593
Deferred income taxes	2,802		3,170
Deferred cloud computing contract incentive	1,250		4,250
Other (1)	6,183		11,415
Total other non-current liabilities	$	34,448	$	44,428

(1)Includes $2.9 million as of December 31, 2020 in certain payroll taxes under the Coronavirus Aid, Relief and Economic Security ("CARES") Act. The 2020 balance is due December 31, 2022.