As we get closer to the end of the year, it's time once again to take a good look at your investment for possible tax actions.

There are two factors to consider this year. The first of these is personal: an informed guess about your income situation. If you expect your income to be significantly higher in 1981, you may want to take steps to reduce next year's income while increasing 1980 income.

To exercise this strategy, you may want to take capital gains this years and postpone losses until 1981. Remember that to generate a gain for your 1980 tax return, you must sell a security no later than December 23. A sale that produces a loss may be made as late as December 31.

But there is a compliating factor. Unless there is a dramatic change in economic conditions between now and January, a tax reduction bill is likely to emerge from the Congress early next year.

One of the probable changes will be a general tax rate reduction -- so you have to guess at the impact this may have on your 1981 tax liability.

Regardless of the tax climate, there is a general rule: In capital gains, long-term is better than short-term, while the reverse is true for capital losses.

In addition, if you are planning year end moves, remember that a "wash sale" -- purchase of the same stock within 30 days before or after its sale -- prevents you from claiming any tax advantage.

Despite the built-in uncertainties, you should be taking a look at your portfolio and considering actions to reduce your combined 1980-81 tax bill. But keep in mind that for most people, tax implications, should be a secondary factor in developing a wise investment program.

Question: I recently heard that the higer your tax bracket, the greater risk you can take with your investments. How come?

Answer: There are two reasons for this -- one overt, the other implied.

It seems reasonable to assume that if you're in a higher tax bracket, you have greater income than a person in a lower bracket.

In that event you should be in a better position to absorb losses. Unless you blow your entire stake on one long shot, it is likely that a loss will not have the traumatic effect on your capital that it would for someone with a smaller estate.

Second, the higher tax bracket itself reduces your exposure to loss because the federal and state governments are really coinvestors with you.

Through the magic of the capital loss tax concept, you can reduce your tax bill by subtracting from taxable income all or part of your investment losses.

Here's where your tax bracket enters the picture. If you're in the 28 percent federal tax bracket, then Uncle Sam will pick up the burden to the tune of $14 for every $100 you lose.

This assumes you owned the investment for more than 12 months. If it was a short term loss, the tax saving would be $28 per $100.

But if you're a high-income taxpayer in, say, the 54 percent bracket, then your federal income tax would be reduced by $27 (or $54 short-term) for each $100 of investment loss.

In either case, of course, you would also have a similar, though smaller, tax saving on your state income tax.

From this example you can see that a taxpayer in a higher tax bracket has less exposure to loss than a lower-income individual in the identical investment.

My personal investment philosophy is that the only person who can afford to speculate is the one who no longer needs to.

That is, one who has little reserve capital for investment can't really risk losing it. Unfortunately, that's the very person who most feels the need to make a killing and therefore the one who is most easily tempted to take unreasonable risks.

On the other hand, the person who can afford a high risk of loss already has enough so that if the loss materializes it won't have any significant impact on his or her capital base or lifestyle.

But that means to me that a corresponding gain won't have a significant impact either. So why bother? (I except those who get their kicks out of the playing of the game itself rather than from the result.)