Dress becomes fashion rather than costume only when unregulated by law

Evidence

The spread of affluence, particularly in the West, makes it possible for large numbers of persons to choose among the abundant variety of clothing styles available. And the absence of legal support for dress regulations allows them to do so freely. … This last mentioned factor-the absence of legal support for dress regulations-is perhaps one of the most crucial factors. Given this absence, costuming becomes not a matter of law-written or unwritten-but a matter of fashion, that is, a matter of fad. — Lyn H. Lofland, World of Strangers_ Order and Action in…, 448

Categorization

• XREF: Connects to the reader’s article on cross-cultural moral panics over immodest dress and sumptuary laws — this passage states the inverse causal mechanism (absence of legal support turns costume into fashion).
• ADDENDUM: Directly extends ‘Complaints About Immodesty Go Way Back’ — where that article tracked legal dress codes, this passage explains what happens when those laws vanish: costume collapses into fad.