Tax to implement police power

Distinguishing tax and regulation as a form of police power, the determining factor is the purpose of the implemented measure. If the purpose is primarily to raise revenue, then it will be deemed a tax even though the measure results in some form of regulation. On the other hand, if the purpose is primarily to regulate, then it is deemed a regulation and an exercise of the police power of the state, even though incidentally, revenue is generated.

The conservative and pivotal distinction between these two (2) powers rests in the purpose for which the charge is made. If generation of revenue is the primary purpose and regulation is merely incidental, the imposition is a tax; but if regulation is the primary purpose, the fact that revenue is incidentally raised does not make the imposition a tax. (G.R. No. 173863)

The public purpose of a tax may legally exist even if the motive which impelled the legislature to impose the tax was to favor one industry over another.  It is inherent in the power to tax that a state be free to select the subjects of taxation, and it has been repeatedly held that "inequities which result from a singling out of one particular class for taxation or exemption infringe no constitutional limitation." Taxation has been made the implement of the state's police power. (G.R. No. L-75697)