Both companies improved their operating ratio in the fourth quarter, with CSX's declining to 66.9% from 71.6% in the same period last year while Union Pacific's declined to 62% from 63.2%.

Both Union Pacific and CSX have done a good job of producing high profit margins. But Union Pacific has been more effective with its pricing power, perhaps because of its particular exposure ...

Yet as energy prices have soared, both Union Pacific (UNP -0.82%) and CSX (CSX 1.71%) have seen demand for more fuel-efficient rail shipments climb, and both companies have sought to take full ...