Each stage of compression should develop the same pressure ratio as all other stages. When a stall occurs the front stages supply too much air for the rear stages to handle, and the rear stage will choke. If the angle of attack is too high, the compressor will stall. The airflow over the upper airfoil surface will become turbulent and destroy the pressure zone. This will decrease the compression airflow. Any action that decreases airflow relative to engine speed will increase the angle of attack, increasing the tendency to stall.
If there is a decrease in the engine speed, the compression ratio will decrease with the lower rotor velocities. With a decrease in compression, the volume of air in the rear of the compressor will be greater. This excess volume of air causes a choking action in the rear of the compressor with a decrease in airflow. This in turn decreases the air velocity in the front of the compressor and increases the tendency to stall.