{"id":1760,"date":"2014-12-21T18:17:37","date_gmt":"2014-12-22T02:17:37","guid":{"rendered":"http:\/\/www.artsjournal.com\/worth\/?p=1760"},"modified":"2014-12-21T18:17:37","modified_gmt":"2014-12-22T02:17:37","slug":"problems-with-data-measuring-diversity","status":"publish","type":"post","link":"https:\/\/www.artsjournal.com\/worth\/2014\/12\/problems-with-data-measuring-diversity\/","title":{"rendered":"Problems with data: measuring diversity"},"content":{"rendered":"

\"just<\/a>Diversity – in audiences, employees, and boards of trustees – matters to arts administrators, and to researchers who study organizations and societies. But how do we measure<\/em> diversity?<\/p>\n

The diversity index<\/em> is constructed like this: suppose everybody comes from one of four different population groups: Blue, Green, Purple and Red. Let the fraction of the population that is Blue be given by B, the fraction that is Green be given by G, and so on, where B, G, P and R are all numbers between zero (if nobody comes from that group) and one (if everybody in the population comes from that group). The diversity index D is found by taking<\/p>\n

D = 1.0 – B2<\/sup>\u00a0– G2<\/sup>\u00a0– P2<\/sup>\u00a0– R2\u00a0<\/sup><\/p>\n

If B = 0.4, G = 0.3, P = 0.2, and R = 0.1, then the diversity index D = 1.0 – 0.16 – 0.09 – 0.04 – 0.01 = 0.7. A lower value for D means less diversity. The lowest number D could be is 0 – that would be the case if everyone came from one group and nobody came from any of the others. For a population with 4 groups, the highest D could be is 0.75 (that’s what you get when B = G = P = R = 0.25).<\/span><\/p>\n

The diversity index has a lot of use across the sciences. Biologists can use it to compare the diversity of plant and animal species in an eco-system. Economists studying industrial organization can use it to measure whether a sector is highly concentrated amongst only a few firms (i.e., if most sales come from just one or two firms, rather than being spread equally over many firms).<\/p>\n

And of course we can use it to measure diversity in populations, either in general, or specifically regarding audiences or employees, and where the groups can be defined by race and ethnicity, or by religion, for example.<\/p>\n

This all sounds straightforward, but in fact there is a big problem underlying it. To illustrate, let’s take a recent post from Richard Florida at City Lab: ‘The Link Between Religious Diversity and Economic Development<\/a>.’:<\/p>\n

How does religion, and especially religious diversity, affect our economies?<\/p>\n

I decided to take a look using data from the Pew Research Center\u2019s Religion & Public Life Project on \u201cglobal religious diversity<\/a>.\u201d The Pew data track the level of religious diversity, measured as the percentage of the population that belongs to eight major religious groups in countries around the world. These include the five major world religions\u2014Buddhism, Christianity, Hinduism, Islam, and Judaism\u2014which account for about three-quarters of the world\u2019s population, as well folk or traditional religions, the religiously unaffiliated (atheists, agnostics, etc.), and other religious groups (Baha\u2019i, Sikhism, Taoism, etc.). …<\/p>\n

Five key findings jump out from this analysis.<\/p><\/blockquote>\n