We've all heard that corporate income is subject to double taxation; once at the corporate level and again at the individual level after dividends are distributed. Congress has put in place a dividends received deduction to mitigate a similar problem at the corporate level.

In what situations does this deduction apply?

How many times is such income subject to taxation?

If double/triple/etc. taxation is so onerous, why are limits in place on this deduction?

If this is okay at the corporate level, why, in your opinion, hasn't it been implemented to mitigate against double taxation when paid to individuals?