There has been a lot of discussion about a recent Science paper on the effect of online access to scientific publications. In the abstract, the author claims that with time, fewer and fewer articles and journals are cited, even though the number of journals and articles has been increasing to now about 2.5 million articles in roughly 24,000 journals every year: This author thus tells us that the number of articles in reference lists is decreasing. This conflicts with a more recent study, which also received some attention, claiming that citations rise: "We find that the average number of citations in reference lists has increased gradually".

So one study finds decreasing citations and anther finds increasing. I'm not an expert in the field of citation analysis, so I can't answer the question: Which one is it? Up or down?