1-Why do Externalities cause market failures ? How ? ( explain and justify , 4-5 lines paragraph) 2-Give 1 example of a negative externality and explain briefly ( 2-3 lines each ) 3-Give 1 example of a positive externality and explain briefly ( 2-3 lines each ) 4-What is a free rider ? Does it apply to a negative or positive externality ? Why is it mostly associated with public goods ? ( 5-6 lines paragraph)