Relatedly: Does such an index exist?
Relatedly: What are relevant graphs / metrics / data on those variables?
[Question] What could a World Unification Index track to measure how unified the world is, was, and is becoming?
I have the impression that the more unified the world is, a) the less likely wars are, b) the easier it is to coordinate to solve global problems. It would also create more economic prosperity. But some forms of globalisation could also make our civilisation less robust. Anders Sandberg says the extent a feature is globalize should be proportional to the extent that feature’s impact is global (https://www.youtube.com/watch?v=91FKgBURAV0).
I think a careful definition of just what unification will mean in this context. Based on a number of the metrics you list we could view just about every empire as a form/attempt of world unification. But that view strikes me as being very different from a world where people are freely moving and interacting with one another on a peaceful and largely voluntary basis.
I think the other important question here might be the end point—what is such an index telling us or to be used for.
My view is that a fully unified world, on pretty much any definition I can think about, is unstable. So if the goal were to maximize the unification index that might be a very bad plan. If it was used to start tracking where we might start seeing increased tensions that might lead to increased global conflict/world war type outcomes perhaps it becomes a useful tool.
Of course, that is in the abstract as I’m not sure just how such an index would be assembled or over what time periods any given construction would be valid.
One strong indicator of globalization is trade. The WTO maintains a set of global trade indicators, which has data on trade flows, trade disputes and tariff levels going back to 1948.
Some variables I would be interested in seeing tracked include:
the distribution on the number of people a person can communicate with (without translators; both fluently and at a basic level)
how good and easy to use translators are getting (including audio<>text conversion)
how much countries are legally merging (ex.: EU) or fragmenting (ex.: UK?), including level of desire to separate (https://en.wikipedia.org/wiki/Lists_of_active_separatist_movements)
how much art (music, books, movies) are consumed internationally vs locally
how much other cultural elements are getting globally adopted (ex.: food, clothing)
how much international products / services are getting consumed
what fraction of people are multiracial, and multiracial to which extent on average
I’m thinking a few things that are perhaps not super important individually, but ought to have at least some weight in such an index:
Standardization and transportation
What’s the progress of adoption of the metric system?
Relatedly, can we all (including Chile, where I live) ditch US paper sizes and switch to ISO sizes?
Standardizing electric plugs and outlets, as well as domestic alternating current frequency and voltage
Low priority, but probably still desirable if one wants a truly unified world: everyone driving on the same side of the road
For rail transport: reduce variety in track gauges, electrification (which is different from residential use), and signaling systems. It is probably impractical to make *all* rail be standard gauge (1435 mm), as there are use cases where broad or narrow gauge is useful (e.g. in mountain railways there is often not enough space for standard-gauge tracks). But you could still say, for example: “okay, all new narrow gauge is going to be 1000 mm from now on”, while converting railroads in countries like Portugal and Spain (1668mm) to standard.
Aviation freedom: to what extent the https://en.wikipedia.org/wiki/Freedoms_of_the_air are granted between countries. A unified world would probably have something like all eight freedoms everywhere; countries could proceed unilaterally with this, granting foreign carriers parity with local ones in regulatory terms.
Passport strength: how many countries can a holder of a given passport travel to without a visa? I am not sure how to weigh this with regards to the population of the issuing country, the destination countries, their GDP...
Legal cooperation/integration
More countries acceding to treaties that are open to signature by all states: the UN Charter, the two Human Rights Covenants (the US hasn’t signed the one on Economic, Social and Cultural rights and China hasn’t signed the one on Civil and Political Rights; Saudi Arabia has signed neither), several specialized human rights treaties (e.g. Rights of the Children)
International jurisdiction: expanding the jurisdiction of the International Court of Justice (which tries cases between states) and the International Criminal Court (which prosecutes crimes of genocide when national courts fail to do so); expanding and standardizing extradition treaties, enshrining caveats against the death penalty and requiring a fair trial, etc.
International private law: expanding the Hague Conference on International Private Law and its Conventions, such as the Apostille Convention that facilitates recognition of foreign documents
Trade and integration organizations have been mentioned, but I’d like to mention a few specific initiatives: the OECD, which groups the developed countries and the top developing ones (like Chile and Mexico), and the African Continental Free Trade Area (plus Regional Economic Communities)
Cooperation in global issues like the Montreal Protocol, which bans ozone layer-harming chemicals, and global warming. Carbon taxes/tariffs probably should count toward this.
A caveat: while I’ve phrased all of these in a positive light, this does not preclude there being trade-offs. For example, expanding the freedoms of the air would likely boost air travel, which has bad environmental impacts.
Race being a construction, how would you measure this? Perhaps how widely the average person’s genotype is distributed geographically?
Access to public utilities. I’m looking for global power, water, data, transport (both goods and people) and economic networks.