I think if we take a look at this situation from now over the next thirty years we might get a different picture.
$20k is maybe a deposit on a median Oz house (Median $350k?). Would have to borrow $330k plus costs so back up to $350k. At 8.5% (best loan rate) have interest costs of $572 per week. Definitely NOT going to get that in median rent ($350 per week?). So it would cost you $220 per week to own the house ($11k per year). Assuming 8% average capital growth gives $28k growth or $17k net growth in capital position.
On the other hand if you put $20k into solid blue chips (CBA, BHP, Westfield, others??) now and leveraged 50% (conservative) with a margin loan as well, giving $40k total) where would that put you? Assume 12% capital growth plus 5% dividends, gives 17%, or $6.8k capital growth.
From this it looks pretty clear that property will always beat shares if you are looking at buy and hold type strategy with blue chips vs median type houses. Of course, moving away from that into speculation will change things as there are few property deals that will get you a multibagger in the short space of time that spec shares can, or alternatively few properties that will self destruct and lose all their value
Dont assume anything, just invest with the money you have and debt free and it turns into a snowball .... it fun to calculate but at the end of the day you are predicting the future so don't assume anything
I assume 4% yield and 7% capital appreciation but that just something I aim for I don't actually expect it to go that way and
then again it doesn't matter cos I ain't got no debt so aren't worry about income to pay the bank