During the 1840's many came to California in search of gold. They began to come by wagon, horses, and foot. They came in large families and sometimes only friends.
A positive externality or an external benefit that occurs if some of the benefits of the production or consumption of a product spillover into a third party that does not have to pay and even if you don't get vaccinated and others get it first.
While a negative externality or the diseconomy is one that imposes a negative impact and effects on the unrelated third party and due to it imposes the costs to the product and the services of polluting effects.
