SUPPLEMENTAL FINANCIAL STATEMENT INFORMATION

Temporary Investments

Temporary investments with an original maturity of three months or less are treated as cash equivalents and are stated at cost. Temporary investments totaled $879 million and $738 million at March 31, 2016 and December 31, 2015, respectively.

Accounts and Notes Receivable



In millions	March 31, 2016		December 31, 2015
Accounts and notes receivable, net:
Trade	$	2,418	$	2,480
Other	223		195
Total	$	2,641	$	2,675

The allowance for doubtful accounts was $69 million and $70 million at March 31, 2016 and December 31, 2015, respectively.

Inventories



In millions	March 31, 2016		December 31, 2015
Raw materials	$	317	$	339
Finished pulp, paper and packaging	1,223		1,248
Operating supplies	569		563
Other	108		78
Total	$	2,217	$	2,228

Depreciation

Accumulated depreciation was $21.0 billion and $20.7 billion at March 31, 2016 and December 31, 2015. Depreciation expense was $267 million and $304 million for the three months ended March 31, 2016 and 2015, respectively.

Asset Retirement Obligations

There was no material activity related to asset retirement obligations during either of the three months ended March 31, 2016 or 2015.

Interest

Interest payments made during the three months ended March 31, 2016 and 2015 were $136 million and $129 million, respectively.

Amounts related to interest were as follows:



	Three Months Ended March 31,
In millions	2016		2015
Interest expense (a)	$	160	$	159
Interest income (a)	37		22
Capitalized interest costs	7		7


(a)	Interest expense and interest income exclude approximately $9 million for the three months ended March 31, 2015, related to investments in and borrowings from variable interest entities for which the Company had a legal right of offset (see Note 13).