3. Miscellaneous Financial Information
Research and development expenses totaled $1,044 million in 2013, $1,042 million in 2012 and $1,044 million in 2011.
Net income included before-tax aggregate foreign exchange transaction gains of $155 million and $159 million, and losses of $184 million in 2013, 2012 and 2011, respectively.
In 2013, 2012 and 2011, net income included gains of $282 million, $328 million and $292 million, respectively, attributable to the combined effects of LIFO inventory accumulations and drawdowns. The aggregate replacement cost of inventories was estimated to exceed their LIFO carrying values by $21.2 billion and $21.3 billion at December 31, 2013, and 2012, respectively.
Crude oil, products and merchandise as of year-end 2013 and 2012 consist of the following:
| 2013 | 2012 | ||||
| (billions of dollars) | |||||
| Petroleum products | 3.9 | 3.6 | |||
| Crude oil | 4.7 | 4.0 | |||
| Chemical products | 2.9 | 2.9 | |||
| Gas/other | 0.6 | 0.3 | |||
| Total | 12.1 | 10.8 | |||