In Esperanto you can construct many new words from a relatively low number of root-word. Example, with from arbo (tree) and aro (set) you can build arbaro (forest).
My question is three folded:
- What is this phenomenon (building vocabulary from a relatively small number of root words) called?
- Is there a metric or it in quantitative linguistic? What is its name?
- Is there a table with a comparison for different languages, included non-natural ones?