I suspect a lot of questions regarding the metrics used can be found in either the WaPo article this references or the Nature piece the WaPo article is based on

I suspect a lot of questions regarding the metrics used can be found in either the WaPo article this references or the Nature piece the WaPo article is based on: https://www.washingtonpost.com/news/wonk/wp/2018/02/20/using-the-best-data-possible-we-set-out-to-find-the-middle-of-nowhere/ https://www.washingtonpost.com/news/wonk/wp/2018/02/20/using... http://www.nature.com/articles/doi:10.1038/nature25181.epdf?referrer_access_token=ymbRxnz9zrlLgXUIZSErjdRgN0jAjWel9jnR3ZoTv0Nro_3a2_QnHhoi4tmpV4YMThej2zn3HuD6JN5yUCKyoEn8Hh54UuPRPq31j83atkeBxCzjyGlSHVauT5umbpzjjwPxv8_DF57JNW453vRpaF6geg9BYzab4Y9zEjEsT16chcsqI4VCZk9gIFqK6-mJV7EOGvlR-LeGKSQp5in2YUKRIwjexV8tsh70tlGczDxwGz_oJ6S0R5nu2oANwAwdpCkf2FqC-kdm-JKYuIGE_Yw2otVw_AIRbsvfzqIxKpXCUGJHQ7sgF8vYeH7nfTWHkU6HJwAGyrPt04f1Ioc7DFwyGtap8E7hIPCP6WRE3EaoXSZOaRMDTxjJxEX1333_5dDfp9fRI3_meJr263ljp2O3uuJXthpUkT5v-R3-l6SaMqYEmImS6ww7QXXYGaqz&tracking_referrer=www.washingtonpost.com http://www.nature.com/articles/doi:10.1038/nature25181.epdf?...