Maybe not, maybe you just think they are:
Leading papers in a journal’s issue attract, on average, more citations than those that follow. It is, however, difficult to assess whether they are of better quality (as is often suggested), or whether this happens just because they appear first in an issue. We make use of a natural experiment that was carried out by a journal in which papers are randomly ordered in some issues, while this order is not random in others. We show that leading papers in randomly ordered issues also attract more citations, which casts some doubt on whether, in general, leading papers are of higher quality.