Again, it depends on elasticities. Businesses can't just raise prices and expect demand to remain at old levels. People quickly substitute goods and services in the face of price changes. In the case of mcdonalds price increases cause people to cook or eat food that doesn't need to be prepared. In the case of rent, supply is fixed, so landlords are already charging monopoly prices. There is very close to zero wiggle room for landlords to raise prices.