I am one of those who believe that it is impossible to find a ten-euro bill on the floor, because someone I believe that there is no opportunity for profit because someone would have already picked it up. . I believe it is impossible even though I found one myself not long ago. Likewise,
Actually, I do not believe exactly these things. But I do believe that lost bills and opportunities for profit do not lay around for long. There is always someone passing by close to them that picks them up. So, I don't let my skepticism stop me from bending down to grab a lost bill, but I think that there are better ways to spend my time than searching for lost bills and opportunities for profit in random places.
Reflecting on Malthus, human population growth and agricultural productivity, Jeremy Cherfas says that he believes that "we are bumping up against" Nature's limits. I believe that if we were bumping against Nature's limits there would be people picking the opportunity this brings to make a profit, and the steps taken by these people would result in higher long-term prices of land or fertilizers or whatever might limit agricultural productivity. And we are not seeing those increasing prices.
I believe there are better ways to spend my time than searching for future scarcities. And I would be worried about future scarcities of natural resources if I saw people betting real money on them - and I mean much more money than this.