When you play poker to you get paid for your labor? or for your service to the other players? Does the zero-sum nature of the game depend on whether a player tried to cheat? or does it depend on whether a player is a great bluffer? No Ron
In order to get it to add to 0. you have to factor in all resources that are currently not being exploided because, a. they're too far. or b. they're too deep. Once you figure that out, you have to bring it to present value, considering the cost of developing the technology that will allow you to get it. Many companies whose stock is listed in many of the worlds exchanges are engaged in finding those resources, developing the technology necesary to get those resources, training the people who are going to get those resources, or providing liquidity to the whole system [...just to name a few] To that, you have to add the potential of new findings. When you consider that in Saturn's moons you can find oceans of methane and natural gas... the question is, how long before the technology is available at a cheap enough price to exploid it? It's imposible to consider all possible values and therefore get to a 0 sum game. The universe is way too big.
A housing bubble is inflationary. Higher home prices means more money (credit) created. Decreasing home prices is deflationary as credit is destroyed. I don't see how this is 0 sum.