[anonmeow]

When the civilization is confined to one small planet while hitting the physical limits to growth, the fixed pie is a good analogy.

There is fixed and diminishing amount of arable land to grow the wheat and apples. You can make only so many pies.

[nickff]

Arable land is a particularly bad example of a justification for a 'fixed pie'. Highly developed countries such as the USA have upwards of eight times the crop yield per acre compared with developing countries, and yield appears to be increasing everywhere. In fact, yields are improving so much that the amount of land dedicated to crop production worldwide has already or will soon begin decreasing.