Roko:

If the growth above inflation isn't defined in terms of today's standard basket of goods, then is it really growth? I mean if I defined a changing basket of goods that was the standard one up until 1991, and thereafter was based exclusively upon the cost per email of sending an email, we would see massive negative inflation and spuriously high growth rates as emails became cheaper to send due to falling computer and network costs.

You're asking some very good questions indeed! Now think about it a bit more.

Even nowadays, you simply cannot maintain the exact same basket of goods as the standard for any period much longer than a year or so. Old things are no longer produced, and more modern equivalents will (and sometimes won't) replace them. New things appear that become part of the consumption basket of a typical person, often starting as luxury but gradually becoming necessary to live as a normal, well-adjusted member of society. Certain things are no longer available simply because the world has changed to the point where their existence is no longer physically or logically possible. So what sense does it make to compare the "price index" between 2010 and 1950, let alone 1900, and express this ratio as some exact and unique number?

The answer is that it doesn't make any sense. What happens is that government economists define new standard baskets each year, using formalized and complex, but ultimately completely arbitrary criteria for selecting their composition and determining the "real value" of new goods and services relative to the old. Those estimates are then chained to make comparisons between more distant epochs. While this does make some limited sense for short-term comparisons, in the long run, these numbers are devoid of any sensible meaning.

Not to even mention how much the whole thing is a subject of large political and bureaucratic pressures. For example, in 1996, the relevant bodies of the U.S. government concluded that the official inflation figures were making the social security payments grow too fast for their taste, so they promptly summoned a committee of experts, who then produced an elaborate argument that the methodology hitherto used had unsoundly overstated the growth in CPI relative to some phantom "true" value. And so the methodology was revised, and inflation obediently went down. (I wouldn't be surprised if the new CPI math indeed gives much more prominence to the cost of sending emails!)

Now, if such is the state of things even when it comes to the fairly slow technological and economic changes undertaken by humans in recent decades, what sense does it make to project these numbers into an em-based economy that develops and changes at a speed hardly imaginable for us today, and whose production is largely aimed at creatures altogether different from us? Hardly any, I would say, which is why I don't find the attempts to talk about long-term "real growth" as a well-defined number meaningful.

I.e. Robin's prediction of fast growth rates is presumably in terms of today's basket of goods, right?

I don't know what he thinks about how affordable biological human life would be in an em economy, but I'm pretty sure he doesn't define his growth numbers tied to the current CPI basket. From the attitudes he typically displays in his writing, I would be surprised if he would treat things valued by ems and other AIs as essentially different from things valued by humans and unworthy of inclusion into the growth figures, even if humans find them irrelevant or even outright undesirable.