Before revision:  Our habit-formation model allows for both addictive ( \alpha=1 ) and non-addictive ( 0<\alpha<1 ) habits.
After revision:  Our habit-formation model allows for both addictive ( \alpha=1 prohibits the habit process to decrease and corresponds to the completely addictive model. \alpha=0 makes the habit-formation constraint moot and corresponds to the non-addictive ( 0<\alpha<1 ) habits.