Don't Raise Pre-flop so that Draws Can't Chase?

[davelin]

I was reading this hand which basically brought up the age-old argument not to raise something like AJo pre-flop so that draws will not have the proper odds to chase post-flop. I just wanted to do some quick calculations to shows this is incorrect.

Assumptions -
1) Including you there are six players to the flop
2) You hit your top pair hand 1/3 on the flop, the other 2/3 of the time you're check/folding.
3) When you don't raise pre-flop, no one has the odds to chase their draws so they all check/fold.
4) When you do raise pre-flop, one person now has the odds to chase and will out draw you 20% of the time.
5) The drawer will not call a bet on the river when he misses.
6) You will still call one bet on the river even if he hits his draw.

So the in the case of not raising -
a) Hit your top pair hand = 1/3 * (5SB)
b) Miss your top pair hand = 2/3 * 1SB
Net profit = 1 SB

In the case of raising pre-flop
a) Miss your top pair hand = 2/3 * (2SB)
b) Hit your top pair hand = 1/3 * (10SB)
c) Drawer doesn't hit his draw = (4/5 * (3SB)
d) Drawer hits his draw = (1/5 * 5SB)
Net profit = 3.4 SB

So clearly the better play is to raise pre-flop.

Comments on my math?