Assuming OP means, "The government will try their best to keep house price increasing" although I'm aware that the use of the word pegged is confusing.

A common opinion is that governments feel that increasing house prices will keep the voters coming in as people work their butts off to get onto the housing ladder (escalator) and then want the bubble to keep expanding as it's their main form of savings. Western society is all in on the Ponzi scheme here.