remainder of society. Water contamination from plants and industrial facilities is another model. All customers are totally aggravated off by contamination yet are not remunerated by the market for this harm. A positive externality is the point at which a singular's utilization in a market expands the prosperity of others, yet the individual doesn't charge the outsider for the advantage. The outsider is basically getting a free item. An illustration of this may be the loft over a bread kitchen getting the advantage of happiness from smelling new cakes each day. Individuals who live in the loft don't repay the bread kitchen for this advantage. [1]