A government can impose various restrictions that will lead to an imbalance in the quantity and price equilibrium resulting in a deadweight loss.
These interventions include:
A price ceiling is the highest price at which it is legal to trade a particular good or service.
Assume that the demand and supply of housing determines the equilibrium rent of $550 a month and the equilibrium quantity of 4,000 units of housing.
The following graph shows the efficient housing market with maximum consumer and producer surplus.

Suppose the government imposes a rent ceiling of $400 per month which is below the equilibrium price. As a result the following changes happen.

A price floor makes it illegal to pay a price lower than a specified level. An example of price floor is minimum wage.
Let’s say the equilibrium wage rate per hour is $5 at the equilibrium quantity of 5000 workers.

Minimum wage is imposed at $7 per hour. The graph will change as follows:

Taxes will increase the equilibrium price and decrease the equilibrium quantity, creating a deadweight loss.
A production quota is an upper limit to the quantity of a good that may be produced in a specified time period.
With a production quota, the quantity decreases, the consumer surplus shrinks, the producer surplus expands, and a dead weight loss arises.
Subsidies are payments made by governments to producers such as farmers. Subsidies lower the prices paid by buyers and increase the prices received by sellers. With a subsidy, the quantity increases, and a dead weight loss arises due to overproduction.