I am not fully familiar with referencing rules of Wikipedia but looking at this Wikipedia page our referencing policy is far less strict.
- We require referencing in order to avoid plagiarism. Plagiarism is generally discouraged by SE in general and Economics.SE (although this does not seem to be your case).
- Next we encourage sources in cases where:
... for answers that talk about statistics, research or results that are not common knowledge in economics (i.e. something that a person with undergraduate degree in economics should know) and which are not self-contained (e.g. it should not apply to self-contained answers presenting a model), and which lack any references to credible sources supporting the answer.
If the answer does not have sources it won't get automatically deleted. It will just get post notice encouraging other users to edit and improve it. If you do not have time for adding sources then why should not other members of community step in and add those? The post notice does not automatically marks the answer for deletion and the answer is still able to receive upvotes.
Next, you talk about enforcing, but let me stress again nobody forces you to add those sources. You won't get banned for not adding sources. Your question won't get deleted, by moderators (but could be by community or Roomba if it gets too many low quality flags).
I would hardly call this 'enforcement'.
There are also no cease and desist notices. The notices and comments encourage you to edit answer, in none of the comments or notices is there any mention or even insinuation you should not attempt to answer the question.
Notices like these are common across all science stacks. Just take a peak at History.SE where they not just use the notice but also actually enforce it by closing or deleting the answers outright by moderators (here your answer will not be deleted at all except if by users).
Next, the notices are encouraging not discouraging, they encourage you to improve the answer by adding references. That is why they exist in the first place. We encourage answers that are based on facts, theory, sources and literature in general. This to maintain some minimum standards of the site, every science Stack Exchange I know of has a variant of this, and I dare to say that the way how we handle this on Economics:SE is one of the most light touch approach among science stacks.
In addition, note that we do not require that you make proper academic citation with ISBN etc like Wikipedia does. If you can put a hyperlink to paper, book or article from some credible medium or heck even just to dataset/graph that is generally enough. And this is not required for self contained answer based on some model and so on as mentioned above.