Sunday 22 June 2014

How Many Lindy Hoppers are There

I've been wondering about this question for a while but with a little free time I finally got around to having a decent crack at working it out with some GIS and statistics.

The short answer: by my estimation about 120,000. Read on for the longer answer.

Where are people Lindy Hopping?

This is actually a somewhat difficult question. Scenes are constantly starting and folding - such as scenes in college towns in the US and those where expats are the primary drivers and consumers.* Plus the advent of the travelling lindy hopper has led to many camps being held in places that don't have a regular scene. For this purpose a "scene" is a location that actually has some form of regular Lindy hop be that classes, social dancing or some other organising activity.
Herrang only has dancing 5 weeks out of the year - that doesn't count. (photo by Rikomatic)
My starting point was the World Lindy Hop Map which I supplemented with maps for countries and smaller scenes including the LA Lindy Hop Map, The Lindy Hop Map Australia, Lindy Hop and Swing Dance in Italy, and the UK Lindy Map.

Next was quality control.

I ended up removing a whole bunch of points. There were plenty with incorrect geocoding (e.g. suburbs of cities that were coded to small towns, country entries sitting in the middle of nowhere etc.), I also did a fair bit of checking to ensure currency of schools, events, etc.** Finally I did a bunch of research to add new venues, website links and cover as broad a geography as possible.

The final result was 827 organisations, dance schools or other evidence of regular lindy hop activity in a particular location. I'm sure I've missed plenty of organisations in local areas - but my mission was to see if a location had lindy hop, not how many dance schools/societies were there.

Guess the map projection and you get a gold star.
As I don't plan on keeping this updated I'm not going to put it on google maps. However here is the data in kmz and shapefile format for those who wish to use the data in your own projects and maps. I've made my best effort with this data, but it's necessarily incomplete and the locations are rather approximate - don't use this for driving directions or holiday planning without further research!

How many Lindy Hop scenes are there?

Obviously, these locations aren't all individual scenes. Recognising that some scenes are supported by 1 large organisation and others by many smaller ones I wanted to get at the number of geographically independent scenes.

First I gathered venues to the nearest urban locality (using data from Geonames) - all those that were within about 15-20km I considered to be part of that locality. I merged a number of these together where the localities were separated by less than 30km - considering that this is probably the maximum distance (as the crow flies) for there to be enough mixing amongst venues for them to be

The answer - 463 scenes spread across 58 countries (or 59 depending on how you count Taiwan) and a range of self governing territories (e.g. New Caledonia, Hong Kong and the Åland Islands).

From this we can see that Lindy Hop is an activity for the relatively wealthy in the world - here is a chart of lindy hop prescene graphed against the Human Development Index***:

How many lindy hoppers are there?

Given the data I've generated here's a related question: How many people could lindy hop if they wanted to? To assess geographic access (leaving aside demographic and cultural factors that affect access) to the above listed venues I applied the World Population Layer to determine the number of people living within 15km of a lindy hop venue. The result: about 308 million people.

Now onto the number of lindy hoppers. Rather than try and guess the average scene size (which can be tricky) I've applied some fancier statistics and a Monte Carlo simulation to get a bounded guess. There's a more complete explanation and the code I used in a short R script I wrote here.

The assumptions I made are:
  • The size of lindy hop scenes are lognormally distributed. (Not bad - but without any data on actual scene sizes is untested)
  • The largest scene size is 5000. (This has been oft quoted in relation to the size of Seoul's lindy hop scene but London and LA/Orange County could also have sizes somewhere in this vicinity)
  • The median scene size is somewhere between 50 and 150.
  • The total number of scenes are 463.
The Monte Carlo simulation generated a stochastic set of 50,000 international lindy hop communities by randomly sampling the median scene size (from a uniform distribution) and then randomly sampling individual scene sizes (from the lognormal distribution) to get a total population of each. This then allowed statistics to be generated

This gives a median of 118,000 and a 90% chance of the "true" number being being between 82,000 and 153,000.****
Only 2% of lindy hoppers made it to Frankie 100. (Photo by hoptothebeat)

So now it's over to you. Can anyone else come up with a better answer?

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* South Asia is a great example. I know of Lindy Hop being taught at one stage or another in Kathmandu, Mumbai, Dhaka, Chittagong, Bangalore, Dharamsala and Delhi at one time or another but combining short ex-pat contracts with a culture where partnered dancing is highly unusual it typically hasn't stuck around.

**It doesn't help that there are literally hundreds of dance schools and other organisations out there whose websites seem to have been created back when geocities was popular and left unchanged (except for content updates). Seriously people, if wordpress is too hard for you spend the money on a web designer.

*** And in those countries with Medium Human Development the lindy hop tends to be located in wealthier cities. This is probably also the case with lindy hop in countries with High and Very High Human Development.

**** The average and the mode were also about 118,000.