SIAM journal articles have doubled in length in the course of my career. At least this is true of the three SIAM journals I’ve checked, those on applied mathematics, numerical analysis, and scientific computing.
Opinions vary as to what has caused this expansion and whether it is good or bad. Certainly the arrivals of TeX (1980s) and electronic publishing (1997) have helped enable the trend. In my opinion the essence of the matter, however, is growing professionalization. These days all i’s must be dotted, all t’s must be crossed, and all referees must be satisfied. Clarity of writing, indeed clarity of thought, must compete against many other worthy concerns. A light, clear 10-page paper is easily shot down. A weighty 25-pager can withstand heavier ammunition.
[13 June 2015]