The description of the new nonexpert-tag is:
For questions that are not about formal economic or econometric models and techniques, their implementations using programs and languages or do not include references to, are not about data standards, or are not based on academic sources.
Arguable, this description clashes with the everyday meaning of the term "non-expert." However, it seems to be the informal meaning that guides the very active retagging effort currently going on. Many undergraduate questions get tagged this way, even though Edgeworth-box economies and IS-LM are most definitely formal models.
The distinction in the tag-description is quite useful. I don't mind answering clearly defined elementary questions; but I have little interest in the kind of questions that are properly tagged with nonexpert. The tag is for informal lay-questions, not beginners. Please use the tag porperly.