If your objective is to earn substantial money as a second income, then you are better off purchasing cryptocoins with cash instead of mining them, and then tucking them away in the hopes that they will jump in value like gold or silver bullion. If your objective is to make a few digital bucks and spend them somehow, then you just might have a slow way to do that with mining.
But the rate is not expected to be kept: sometime in 2018-2019 Ethereum will be switched from Proof of Work to a new consensus algorithm under development, called Casper that is expected to be more efficient and require less mining subsidy. The exact method of issuance and which function it will serve is an area of active research, but what can be guaranteed now is that (1) the current maximum is considered a ceiling and the new issuance under casper will not exceed it (and is expected to be much less) and (2) whatever method is ultimately picked to issue, it will be a decentralized smart contract that will not give preferential treatment to any particular group of people and whose purpose is to benefit the overall health and security of the network.
The following Terms and Conditions (“Terms”) govern the use of the Ethereum open source software platform (“Ethereum Platform”). Prior to any use of the Ethereum Platform, the User confirms to understand and expressly agrees to all of the Terms. All capitalized terms in this agreement will be given the same effect and meaning as in the Terms. The group of developers and other personnel that is now, or will be, employed by, or contracted with, Stiftung Ethereum (“Stiftung Ethereum”) is termed the “Ethereum Team.” The Platform will be developed by persons and entities who support Ethereum, including both volunteers and developers who are paid by nonprofit entities interested in supporting the Ethereum Platform.