Creative Taxation on Capital Gains

Capital gains taxing has been a hot-button topic for as long as I can remember. Cuts in the rate benefit the rich disproportionately. But they benefit anyone who holds mutual funds or IRAs or any other security, property, or commodity with the potential for eventual profit. One major problem is creating a tax-rate has always been a shot in the dark - 36%, 28.2%, 21.4% - proposals fly based on predictions of expected income, which are tied to the performance of the economy, and are therefore unpredictable.
The main problem is created by profit-driven speculators. Reducing the capital gains rate across the board benefits those who buy stocks for a day and sell them the next, which doesn't benefit the company at all - and represents a very small portion of the population.
If the goal of our government (as it has been stated by many) is to encourage long-term investment, which benefits industry, which creates jobs, which improves our economy, and on and on; then there is an easy way to do that.
Instead of creating a new rate, tax capital gains at the prevailing tax rate. If a security or property is held for over 2 years (even 1 day over), divide the tax rate by 2. If held for 3 years, divide by 3, and so on. That way, a capital gain realized after a taxpayer in the 28% bracket, who sells a house held for 4 years would be 7%; if held for 28 years, it would only be taxed at 1% - which encourages holding long-term, which prevents someone from becoming financially house-bound, and the rate is EASY to figure out, even by someone completing their own taxes.
Taxing gains on anything held less than 2 years at the prevailing tax rate, instead of a reduced rate, should much more than make up for any loss of future income due to this program - and if speculators hold investments longer to avoid the higher tax rate, that's good for everyone.