Does the "housing shortage" rule suggest that you should often refrain from buying hotels in monopoly?
From the Official Rules of Monopoly (my emphasis):


  The bank has a fixed supply of 32 houses and 12 hotels. If more players decide to build more houses at the same time than there are houses in the bank, the houses are auctioned off one at a time to the highest bidder. This rule favors the owners of expensive properties, for which the houses cost more in the first place, because the auction price of a house is not tied to the value of the property on which it will be placed. It is not possible to buy more houses than there is available in the bank. This could stop people buying hotels in the future!


and here:


  When the Bank has no houses to sell, players wishing to build must wait for some player to return or sell their houses to the Bank before building. If there are a limited number of houses and hotels available and two or more players wish to buy more than the Bank has, the houses or hotels must be sold at auction to the highest bidder.


Update: - Interpretation and application

I see the purchase of hotels in Monopoly as an endgame tactic, not a mid-game tactic. Similar to a running-game double in backgammon by the leader, which is meant not to increase the stakes but to eliminate the opportunity for the opponent to get lucky and squeak out a win. The purchase of hotels is properly done when one is already firmly in the lead, and thus that the housing shortage period of the game (a possible definition of the mid-game period actually) is already past. 

One then buys hotels because opponents do not actually have enough money to purchase the released assets. By further increasing one's rents one can increase the pain of each landing on your property, and reduce the opponents' opportunity to rebuild a cash stock.