The tax revenues from marijuana in states where it has been legalised are relatively sizeable - is this one of the reasons why many places are consenting to pro-marijuana legislation?

The legalisation of marijuana isn't just about liberal values - it's about dollars

On Tuesday, Oregon, Alaska and Washington D.C. voted in favour of pro-marijuana legislation. A vote in Florida won 58% support, falling just short of the required 60% threshold. Nearly 18 million Americans now live in states where marijuana is fully legal.

Tuesday’s midterms were dominated by the Republicans.

NCSL (@NCSLorg) #NCSLelections - Democrats will control the lowest number of state legislatures since 1860 #2014elections

So, why is it that legislatures and voters in red states favourably lean towards what, on paper at least, would seem to be a liberal issue? One reason (at least when it comes to governments) might be to do with money.

One of the states they now join is Colorado, where marijuana was legalised (with some restrictions) last year. On average, the state now gets more tax revenues from the plant than from alcohol.

The bottom line is there is a potentially sizeable crop of dollars waiting to be had from the legalisation of drugs. There’s a lot more green in the pot than meets the eye, if you will.

The graphic below looks at how this money stacks up around the world compared to other crops.

Methodology

We scored some data on yearly harvested area, production weight and wholesale value for the most common food crops from the UN Food and Agriculture Organization, and used it to calculate yield per km2. Then we went sniffing around in various UN World Drug Reports and performed some backroom calculations to cook up some broadly comparable figures for illegal drugs – cocaine, heroin and the mighty marijuana. Data on illicit substances is, like the peeps who sell them, more than a bit sketchy. For example, the UN data on dried coca leaf production (the raw material for cocaine powder) is based on only the top three coca-producing countries – Bolivia, Colombia and Peru. And the price and purity of coke varies, so we made some assumptions here.

Read more about the project here.

This is a guest interactive taken from the new book, Knowledge is Beautiful (find out more: UK & US), the sequel to Information is Beautiful