Pretending that something doesn’t exist if it’s hard to measure leads to faulty models. You’ve already seen the system trap that comes from setting goals around what is easily measured, rather than around what is important….Don’t be stopped by the ‘if you can’t define and measure it, I don’t have to pay attention to it’ ploy. No one can define or measure justice, democracy, security, freedom, truth, or love.  No one can define or measure any value. But if no one speaks up for them, if systems aren’t designed to produce them, if we don’t speak about them and point toward their presence or absence, they will cease to exist.”

Donella H. Meadows, Thinking in Systems: A Primer, 2008. pp. 176-177