11. Miscellaneous financial information

In 2013, net income included an after-tax gain of $24 million (2012 – $45 million gain, 2011 – $10 million gain) attributable to the effect of changes in last-in, first-out (LIFO) inventories. The replacement cost of inventories was estimated to exceed their LIFO carrying values at December 31, 2013 by $1,787 million (2012 – $1,769 million). Inventories of crude oil and products at year-end consisted of the following:


millions of dollars	2013		2012
Crude oil		628		473
Petroleum products		340		284
Chemical products		54		60
Natural gas and other		8		10
Total inventories of crude oil and products		1,030		827

Net research and development costs charged to expenses in 2013 were $154 million (2012 – $147 million, 2011 – $120 million). These costs are included in expenses due to the uncertainty of future benefits.

Accounts payable and accrued liabilities included accrued taxes other than income taxes of $380 million at December 31, 2013 (2012 - $377 million).