I have always said this is an illusion. Latest today I received an assignment to target the upper middle class, lower middle class and the floating class with the following definition and the number represent the Kenyan current scenario:
Upper Class: forms 4.8% on >$20
Upper Middle Class forms 4.7% on $11-$20
Lower Middle Class forms 8.7% on $4-$10
Floating Class forms 20.9% on $2-$4
Poor forms 60.8% on <$2
..."Wewe ni mtu mdogo sana....na mwenye amekuandika pia ni mtu mdogo sana!".