Basically its mostly people in powerful positions that use their power to convert minor contributions to paper credit. There's a list of self reported reasons

Basically its mostly people in powerful positions that use their power to convert minor contributions to paper credit. There's a list of self reported reasons how they achieve this seemingly high productivity, and the most honest bit is probably: * mentorship of very many young researchers * leadership of a research team, or even of many teams * extensive collaboration * working on multiple research areas or in core services * availability of suitable extensive resources and data * culmination of a large project with the latter points giving more transient productivity.