Add gross value added

[l-emele]

Description of the issue

For the scenario fact sheets we need a definition of gross value added (GVA).

Ideas of solution

A definition should probably builds on a definition of economic value (#342).

Workflow checklist

• I discussed the issue with someone else than me before working on a solution
• I already read the latest version of the workflow for this repository
• The goal of this ontology is clear to me

I am aware that

• every entry in the ontology should have a definition
• classes should arise from concepts rather than from words

[han-f]

This is interesting and I think it may open up a whole lot of discussion needs and possibly further definitions.
Some first starting points may be eurostat and Wikipedia:

Eurostat provides the following:
Gross value added (GVA) is defined as output (at basic prices) minus intermediate consumption (at purchaser prices)
https://ec.europa.eu/eurostat/statistics-explained/index.php/Glossary:Gross_value_added

And Wikipedia:
In economics, gross value added (GVA) is the measure of the value of goods and services produced in an area, industry or sector of an economy. Gross value added is the value of output less the value of intermediate consumption; it is a measure of the contribution to GDP made by an individual producer, industry or sector; (...)
https://en.wikipedia.org/wiki/Gross_value_added

[sfluegel05]

From dev-meeting 8.3:
Definition: Gross value added is an economic value that measures the value of goods and services produced in a sector of an economy and a measure of the contribution to GDP. It is calculated as the value of the output less the value of intermediate consumption. (based on wikipedia)

[jannahastings]

Definition: ...

How about (slight change on the proposal above):

Gross value added is an economic value that is the value of goods and services produced in a sector of an economy, measuring that sector's contribution to GDP. It is calculated as the monetary value of products and services produced, less the value of intermediate consumption. (based on wikipedia)