Topics on my mind: May 2018

I've been listening to quite a few podcast episodes lately, particularly Rationally Speaking, the 80000 Hours podcast, EconTalk and Conversations with Tyler (who runs the excellent Marginal Revolution economics blog). I was very impressed by a Rationally Speaking episode with Dr Herculano-Houzel, a brain researcher (here's my blog post about it), as well as the 80,000 Hours episode with Anders Sandberg. Anders does a wide range of very creative and original research; here he was talking about hibernating aliens, interstellar warfare, and how quick colonising the universe could be. I'd previously seen these arguments as intellectually fun but fairly irrelevant. But on the podcast, Anders presented them in a new light: not simply as speculations on what aliens might be doing, but also as a way of exploring strategies that humans might want to use in the far future. Now that I think about it, that does seem pretty important.

I've finally written some political blog posts: an extensive exploration of the causes of the housing crisis, as well as another which I haven't published yet on arguments for libertarianism. The latter is meant to be a holistic summary of my political and economic views, so I'm being thorough in editing it. In general I think that I should spend very little time thinking about or discussing politics, but that's pretty difficult. When tempted, I remind myself that my brain evolved to live in a tiny tribe where involvement in politics was a matter of life and death. Since I instead live in a society of millions of people with a very stable (by historical standards) political structure, personal political action is actually thousands or millions of times less important than my emotions tell me it is.

I've also recently posted on the backpropagation algorithm and ways it might be implemented in the brain - which follows in the footsteps of Jacob's excellent essay on the same subject - and added an index by topic of all blog posts so far.

Following on from my series of posts about intelligence, check out this timeline of milestones in the evolution of life (taken from this blog; note that the scale is a bit distorted though).



Three key takeaways:

• Simple life formed almost as early as it could possibly have, which implies that it's a relatively easy step
• Going from photosynthetic prokaryotes to eukaryotes with nuclei took a very long time. Apparently eukaryotes probably arose from the symbiotic fusion of two cells, which I suppose would be fairly complicated
• Going from eukaryotes to multicellular life was another pretty lengthy step

So it took over 80% of the time between the origin of life and today to get just to something like microscopic algae. I'm not sure how to interpret this. On one hand, the more complex life is, the more scope there is for evolution to make interesting changes (one salient example is how humans ended up in an "intelligence arms race", and thereby developed unprecedented mental abilities very quickly). On the other hand, microorganisms live and die very quickly compared with more complex life forms, so the total selection pressure on them was probably even greater than the time ratio makes it seem.

One last thing on my mind: the causes of increasing economic inequality. The standard explanation I've heard is that as the world becomes more connected and markets get bigger, the returns to success increase in most fields, so elites take a larger share of income. (Power law distributions, generated by processes where "the rich get richer", are often used to model wages; although according to this recent paper, log-normal distributions fit better). First question - if this is true, how long has it been going on? Decades? Centuries? A millennium? Second question - in what sort of futures might the returns to success decrease? Would leveling society require another upheaval like World War 2?

On the other hand, the graphs below suggest that this explanation is wrong, or at least incomplete.



At least until 2010, major continental European countries didn't exhibit the same spike in inequality as anglophone countries. This is measuring pre-tax income as well, so the difference is even greater once you account for the countries in the right-hand graph having more extensive redistribution via taxation and welfare. Is the disparity due to non-anglophone countries discouraging entrepreneurship? Or providing more opportunities to disadvantaged children? Or does it stem from more subtle cultural factors? That's the trillion-dollar question, I guess; and we'll need good sociologists just as much as good economists to solve it.