While his argument seemed reasonable, it would be easy fall victim selection bias by picking the examples that you are well aware of. I wanted to see if there actually was a correlation between gay rights and national prosperity.
Quantifying national prosperity is a common task. I choose GDP (PPP) per capita, GNI per capita, GNI (PPP) per capita, and HDI. HDI combines GNI (PPP) per capita with a education index and a life expediency index.
Quantifying gay rights was harder. I knew of a survey that asked if gays should be accepted, but it wasn't asked in many countries. I thought about using years that homosexuality had been legal or the punishment if it was still illegal. However, as I was looking that up I found this Wikipedia page that listed 7 types of LGBT rights for each country. They are, legality, civil union or similar, marriage, adoption, gays in military, anti-discrimination laws, and laws related to gender identity. Each category has a green check or red x in it for each country. I gave 1 point for a check, 0 for a x, and 0.5 points for both or a ? (eg, the US gets 0.5 for marriage since it's legal in some places and illegal in others). Note here, that regardless of how you feel about those 7 things, it is safe to say that a country with more green checks is more friendly towards gays, and that is what we are trying to quantify here.
The results were pretty similar for each of the 4 measures of prosperity. All were just about a 0.70 correlation between gay rights and prosperity, which is quite high indeed. I used the 125 most populous countries. Just for fun, I also looked at the correlation between population and gay rights, and as expected I found none (-0.04).
|GNI (PPP)||GNI||HDI||GDP (PPP)||Population|
Scatter plots are always fun so here are some of those: