Douglas Harper's Etymology Dictionary
psephocracy
"government formed by election by ballot," from Greek psephizein "to vote" (properly "to vote with pebbles," from psephos "pebble") + -cracy.
Wiktionary
psephocracy
n. government by ballot-elected representatives; representative democracy. (non-gloss definition: Often contrasted with democracy, with which it is unfavourably compared for its lack of demotic participation in the political process outside of elections.)