Only in a centrally planned economy would either be tried, much less both on the same item.

Seventeen Chinese cities have imposed restrictions on buying real estate in the past week as China’s leadership tries to cool a home-purchasing frenzy that is sending prices soaring.

These restrictions come with the justification that demand is too high—there’s too much money running in—for the supply of housing that’s actually available.  And, in addition to increasing the down payment required to get into a house (which should be a bank decision, not a government one (except that the PRC’s banks are controlled by governments at various levels of the hierarchy)), the government is requiring that

families who have two or more properties [are barred] from taking out mortgages and buying more.

By restricting demand in this way, the government also is restricting the supply.  While it’s true that capital projects—house and apartment building, in this case—take more time to come to fruition than money takes to come into the demand side, this artificial restriction on demand eliminates incentive to supply.

The PRC is ignoring the fact that, in a properly free market, supply and demand do a fine job of restricting each other—and at prices satisfactory to both suppliers and demanders.