[gnicholas]

Not at all. Neither of these account for how long you've held something, which is what implicates inflation.

For example, Person A buys stock in Company A and holds it for just over 1 year. Person A's gain on this stock is $1,000.

Person B has held stock in Company B for the last 50 years. He sells at exactly the same time as Person A and has the same $1,000 taxable gain.

If we accounted for inflation, Person B would pay much less tax than Person A, because Person B's gain is mostly (if not completely) inflation. Person A's gain, on the other hand, is mostly real gain, not inflation.