The classical school emphasizes production of goods and services as the key focus of economic analysis. Neoclassical economics focuses on how individuals operate within an economy. As such, the neoclassical school emphasizes the exchange of goods and services as the key focus of economic analysis.. (Source : Difference Between Classical & Neoclassical Economics | eHow) Here's information about the dates of emergence of neoclassical economics:
A random sampling of other states indicates the issue is mixed. For example, Illinois taxes the equipment if it is used in a manufacturing process. In Maine, there is no exemption. In Connecticut, all fire safety equipment is exempt.
Connecticut: Allows taxpayers to totally exempt social security from state income tax if income is less than $60,000 (joint filers). Iowa: In 2013 exempts a certain portion of benefits from income tax. In 2014 the exemption will increase to 100%.