What is the fine-grained topic of the following text: In oil, OPEC along with some other producers including Russia, cut oil output sharply in December before a new accord to limit supply took effect on January 1, it said on Thursday, suggesting that producers have made a strong start to averting a glut in 2019 as a slowing economy curbs demand. Only return the topic.
OPEC and other producers' efforts to limit oil supply and prevent a glut in 2019.