economy is your answer
With the economy, pricing for housing could rise (bad economy), or fall (good economy) per the economy that is happening. It also depends on the supply and demand. If population is on the rise, then the amount of housing is not sufficient, leading to the rise of prices. (demand-push theory). If however, the owner needs to cover his expenses, then he may raise the prices also (demand-pull theory). In the end, it depends on the economy, and how well it is going
hope this helps