C'mon.

That's not bias, that's selective coverage. The term bias in the context of encyclopedia articles means slant, or to use the silly wikipedia terminology, "point of view".

SEP is pretty good about avoiding bias in that sense.

They also don't have Kripke, Putnam or Fodor. I dare say that going by relative prestige in their philosophical cultures, Kripke is a more startling omission than any of the three you mentioned (http://leiterreports.typepad.com/blog/2015/01/most-important...). That's not a point about merit, btw, just about who people would write about if personal articles showed favoritism.

I wonder if there's a tendency to not write articles on living philosophers (as opposed to some particular aspect of their work).

Still, I do suspect there is less work on 20th century Continental philosophy (so far as that's a well defined thing).

'Entries should focus on the philosophical issues and arguments rather than on sociology and individuals, particularly in discussions of topics in contemporary philosophy.'

The lack of those articles is policy not bias because they are contempry philosophers.