Citing non-economics studies in an economics research paper
As long as the main results/conclusions of your paper don't rely solely on the non-economics literature you cite, you should be okay. In other words, it's perfectly fine to use non-economics literature to motivate or even as part of the support for your thesis, as long as you also include proper economic arguments, i.e. theoretical models or econometric analyses.
For example, Bidner and Eswaran (2015) theorized about the origin of the Indian caste system and cited quite a few sociological, anthropological, and biological literature to motivate their model.
Likewise, Caplan and Dean (2008), which provides axiomatic foundations for a neuroscientific hypothesis (that dopamine encodes the &quot;reward prediction error&quot;), is full of references to the psychology and neuroscience literature. The paper even includes an extended review of the non-economic literature and explains how they are relevant for economic decision-making.
Similar examples are plentiful, and they end up in high-rank journals because, notwithstanding their non-economics citations, those papers contain substantive economic contributions.