Variations
This book has mostly discussed what the em era is like as if that era is stable and never changes. But we expect many changes and trends over the em era. For example, the size of the em economy grows exponentially, although this growth may fluctuate more than it does today because of concentration in a few key cities. Also, the cost of computing hardware falls exponentially, and with it the energy used per computing operation, and the natural em body size. parallel computing costs fall faster than serial computing costs, and also faster than the cost of non-computer tools. So there is a trend in workplaces away from using serial computer tools and noncomputer tools, and toward using em minds and parallel computer tools. parallel software becomes more efficient relative to the emulation process, inducing ems to use more software tools. The cost of communication rises relative to the cost of memory and computing, increasing communication delays, and reducing the rate of travel, meetings, and distances between meeting participants. As computing hardware is the main em labor cost, em subsistence wages and median wages fall with computing costs. Thus the speed-weighted size of the em population grows even faster than does the em economy. The typical sizes of firms, clans, and cities grow both with the size of the population, and with the size of the economy. While the first ems run near the speed of ordinary humans, there is an early transition to most ems running at a much faster common speed, estimated in Chapter 18 , Choosing Speed section to be within a factor of four of 1000 times human speed. But during the em era typical em speeds may slowly decline, as the growing em economy creates spatially larger em cities which signals take longer to cross. After an initial burst of exploration, the space of feasible tweaks of em minds slowly grows, but perhaps does not add much value. Added tweaks, random drift in capital per clan, and learning about which clans are best at which jobs should all contribute to a slow increase in the dominance of economy activity by the top few clans. The top clans slowly hold a larger fraction of the jobs, and own a larger fraction of capital.