Theory:  I should increase my 401(k) contributions to the maximum to minimize taxable income and maximize retirement funds.

Supporting Facts:

1. TMND (The Millionaire Next Door) states that the wealthy realize less of their income as a percentage of their wealth compared to the non affluent.
2. 401(k) contributions are taken out before taxes thus lowering taxeable income.

Contra

1. Oppurtunity cost of your money being tied up until 59.5 years of age.  What else could I do with this money?
2. Unknown tax burden at age 59.5.  This would be during prime earning years so it's likey that income may be higher at that time.  Of course I would not need to take that money during that time.