The Tobin Q ratio is market value / replacement cost of assets. The problem is, what is the replacement cost of an Twitter or Uber of Amazon? The cost of the so

The Tobin Q ratio is market value / replacement cost of assets. The problem is, what is the replacement cost of an Twitter or Uber of Amazon? The cost of the software itself is trivial, and yet it would be near impossible to replace either. The whole notion of valuing new-era (or whatever you want to call it) companies using "replacement cost" doesn't make sense. The proponents of Q say that ultimately the profit margins will be so juicy that somebody will start to compete for those dollars. Maybe. There's no evidence of that yet.