Unless the meaning is absolutely clear, avoid free-floating comparatives. If you use “more,” “better,” and so forth, complete the comparison; state what the item is “more than,” what it is “better than.”

Example: In the sentence “In 1992, pancakes cost more,” the meaning is not clear. It could mean that pancakes cost more in 1992 than they did in 1991, or it could be that pancakes cost more than waffles, if waffles have also been mentioned in the paragraph.