I have a fondness for what McKinsey called "crude instruments", something that is almost certainly good enough, and will stop you trying to get ever more precis

I have a fondness for what McKinsey called "crude instruments", something that is almost certainly good enough, and will stop you trying to get ever more precise data. "A crude instrument like this is a pretty good start. It begins to shake things up and overcome the internal inertia." http://www.mckinsey.com/insights/strategy/breaking_down_the_barriers_to_corporate_resource_allocation http://www.mckinsey.com/insights/strategy/breaking_down_the_... There will always be an epsilon to conquer; most of them aren't worth the effort after the first couple approximations, and I value accuracy over precision. "It's better to be vaguely right than exactly wrong" — Carveth Read (1920, predates Keynesian equivalent, q.v. https://en.wikipedia.org/wiki/Carveth_Read https://en.wikipedia.org/wiki/Carveth_Read )