2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/208691I summarize the recent work on market (in)efficiency, highlighting key elements why financial markets will never be made efficient. My approach is not by adding more empirical evidence, but giving plausible reasons as to where inefficiency arises and why it's not rational to arbitrage it away.5 pages, 1 figure. based on a speech at Tokyo Econophysics Meeting, Nov 14th 2000Disordered Systems and Neural NetworksTrading and Market Microstructuretext