You don't have infinite pies, but if you can only consume one pie, a pie and a half might as well be infinite. If everyone has a pie and a half and no one can consume more than one pie, then there is zero value attached to the extra half pie that everyone has. There is even negative value attached to it because the excess pie needs to be disposed of or it will attract vermin and become moldy.
If you can thwart the pie-making abilities of others, such that they can only make half a pie, then your pie and a half is worth more. Thwarting the positive sum efforts of others is part-and-parcel to success with a zero-sum mindset.
If you make infinite pies and give them away for free, then pie-making skills do become valueless.
This is classic monopoly activity. If you have a monopoly, you can extract a disproportionate share of the value added from that monopoly and use that monopoly power to expand into other areas by giving away products,, driving competitors out of business and then charging for what had been given away for free.
To use another example, suppose you have a monopoly in an operating system. You can use revenues from that monopoly to subsidize developing and giving away a web browser. Because of the barriers to entry for web browsers, no one can compete with you with a stand alone browser unless they have revenues from some other source. If no competitors develop a browser (from which they can derive no income), then you have another monopoly and can begin to charge a monopoly premium for your web browser.
If there are a multitude of browsers, some of which are given away, then there is no value associated with a proprietary browser and so there is no monopoly.
The browser market is approximately zero-sum (over the short term). There are a finite number of computers needing a browser, once that need is satisfied there is no additional need. A zero-sum mindset with a monopoly then causes obsolescence so more browsers are needed. A positive-sum mindset makes something new so now there is a browser and something that does something else, a wowser, then a flowser, a smowser, a growser and all manner of other -owsers.
I really want a smowser.
This is the first part of a mini-sequence of posts on zero-sum bias and the role that it plays in our world today.
One of the most pernicious of all human biases is zero-sum bias. A situation involving a collection of entities is zero-sum if one entity's gain is another's loss, whereas a situation is positive-sum if the entities involved can each achieve the best possible outcome by cooperating with one another. Zero-sum bias is the tendency to systematically assume that positive-sum situations are zero-sum situations. This bias is arguably the major obstacle to a Pareto-efficient society. As such, it's very important that we work to overcome this bias (both in ourselves and in broader society).
Here I'll place this bias in context and speculate on its origin.
Where this bias comes from
It's always a little risky to engage in speculation about human evolution. We know so little about our ancestral environment that our mental images of it might be totally wrong. Nevertheless, the predictions of evolutionary speculation sometimes agree with empirical results, so it's not to be dismissed entirely. Also, the human mind has an easier time comprehending and remembering information when the information is embedded in a narrative, so that speculative stories can play a useful cognitive role even when wrong.
Anatomically modern humans appear to have emerged 200,000 years ago. In the context of human history, economic growth is a relatively recent discovery, only beginning in earnest several thousand years ago. The idea that it was possible to create wealth was probably foreign to our ancestors. In The Bottom Billion, former director of Development Research at the World bank speculates on the motivation of rebels in the poorest and slowest growing countries in the world who start civil wars (despite the fact that there's a high chance of being killed as a rebel and the fact that civil wars are usually damaging to the countries involved)
Neither the developed world nor the countries that Collier has in mind are genuinely good proxies to our ancestral environment, but like the people in the countries that Collier has in mind, our ancestors lived in contexts in which growth of resources was not happening. In such a context, the way that people acquire more resources for themselves is by taking other people's resources away. The ancient humans who survived and reproduced most successfully were those who had an intuitive sense that one entity's gain of resources can only come at the price of another entity's loss of resources. Iterate this story over thousands of generations of humans and you get modern humans with genetic disposition toward zero-sum thinking. This is where we come from.
For nearly all modern humans, the utility of zero-sum bias has lapsed. We now have very abundant evidence that the pie can grow bigger and that win-win opportunities abound. Both as individuals and as representatives of groups, modern humans have a tendency to fight over existing resources when they could be doing just as well or better by creating new resources that benefit others. Modern humans have an unprecedented opportunity to create a world of lasting prosperity. We should do our best to make the most of this opportunity by overcoming zero-sum bias.