When OPEC and Russia meet this weekend to gauge progress on their oil-supply deal, they’ll be trying to dispel the shadow of previous unfulfilled promises. Oil prices rose 20 percent in the month after OPEC agreed to cut output, reaching $54.06 a barrel in New York on Dec. 28. Since then, they’ve slipped almost 5 percent as traders, with one eye on rising U.S. shale production , await proof that OPEC and other producers will live up to their deal. They recall how Russia broke its pledge during cutbacks in 2008, while some members of the producers group failed to fully implement the agreement. The solution: The dealmakers have created a panel to verify the cuts, a five-nation group with both OPEC and non-OPEC members that will meet Jan. 22 in Vienna. While some see this as an impressive indication of intent in the midst of a two-year price […]