You may find some answers to your questions -hopefully- in this recently published study:
Fransen, L., Kolk, A., & Rivera-Santos, M. (2019). The multiplicity of international corporate social responsibility standards. Multinational Business Review. Volume 27 Issue 4; Publication date: 9 December 2019
In terms of US-based CSR efforts, there isn't a singular set of standards. There are many certifications related to BCorps and organic/safe quality ingredients and global, ethical frameworks (SDGs, MDGs, etc.) that companies use to substitute for this lack. While not binding, their sustainability reports also benchmark their efforts towards people, planet, and profit.
Not yet to the best of my knowledge. However, il is high time and will be worth while for geographies to share experiences on CSR as is the case with IFRS and CG régulations.
There is none yet to the best of my knowledge. However, il will be worthwhile and appropriate to share practical knowledge and experiences just as it is the case with IFRS and CG regulations.
There are various standards and recommendations regarding CSR implementation and reporting, namely: GRI, EU Directive 2014/95 / EU, ISO 26000, Social Accountability SA 8000, IIRC ...
Why do we single out Corporates for being socially responsible and then audit their compliance? Shouldn’t we expect Government to be socially responsible (GSR)? Educational institutions (EISR)? The charity sector (ChSR)? As well as every individual (ISR)? Many of these social organs are not held to the same standards nor are audited against them. Either CSR is placing an undue burden on one organ of society, or it is a misnomer.