Fred Foldvary asks: Were any economists prior to the 1930s for a pure free
market?

I take his question to really mean "Were there any economists in the period
just before Keynes who were laissez-faire advocates?" (rather than meaning
anytime prior to the 1930s).

While Henry Simons' A Positive Program for Laissez-Faire was not published
until 1934, I suspect his views were pretty well shaped by the late 1920s.
And I will point out that Simons (and Knight) were not fans of central
banking.

Ross Emmett