Yep. The trend over time could equally be capturing changes in referencing practice (either that really important, influential papers/inventions in the past di

Yep. The trend over time could equally be capturing changes in referencing practice (either that really important, influential papers/inventions in the past didn't reference other really important, influential papers/inventions nearly as often as equally novel papers/inventions today, or that modern referencing is much more exhaustive about referencing minor and tangentially relevant papers/inventions. There is, of course, also more significant prior art in journals and patent indices to actually cite in later years...). They carry out some robustness checks, but I'm not sure any of them really dent that hypothesis. It's also a conclusion based on proportions (ie. the effect mostly comes from by there being a lot more "non-disruptive" papers published rather than fewer "disruptive" papers) and there's actually a trend rise in the raw number of "most disruptive" academic papers from the 1950s through to the 1990s, at which point the numbers drop so sharply it looks like a discontinuity in the data (but would probably coincide with lots of journal content becoming easily accessible online...)