Increasing expenditure on defense decreases the money available for other public expenditure. Therefore, if the country is secure for business and investment growth the government should spent its revenue on productive expenditure. This is because defense expenditure does not generate additional income for a country. Thus, the opportunity cost of increased spending on defense is the income which could be generated if the revenue is invested in productive activities like agriculture and infrastructure development.
The equilibrium price is set by the forces of demand and supply. This price is available in a market where there are many