Why is Siberia so sparsely populated?

It's Cold. It's actually extraordinary cold. Winters are lethal. The ground is frozen almost constantly. In the North of Siberia you have tundra which is Continuous Permafrost, in the South its Taiga or Discontinuous Permafrost. With Continuos Permafrost the ground is frozen year round. read more

Much of the Russian Federation is still sparsely populated as both a result of Soviet mismanagement in the early Stalin era and the tremendous human toll the Soviet peoples paid in World War 2 and the earlier Communist Revolution. read more

Just so you know, most of the land in Canada as is most of the land in Siberia is really, really not densely populated. My very quick, totally unscientific search for popl. density maps shows that a goody chunk of Canada, Alaska, and Siberia have popl. densities less than 8 people per square miles. read more