how many over-bidders does it take to start distorting home prices? obviously this varies by region, but curious if there are any general ratios, i.e., 1 over-b

how many over-bidders does it take to start distorting home prices? obviously this varies by region, but curious if there are any general ratios, i.e., 1 over-bidder per 20 home listings, that help gauge the effect on home prices when new money floods in from, say, a company going public (e.g., facebook, google) or from foreign speculators.