The paper by Millis, Littlewood, and Shraiman challenges the traditional "double exchange" model used to explain the resistivity of La1−xSr_xMnO_3. They present a solution to the double exchange model and show that it disagrees with experimental data in several important respects. The authors propose that a strong electron-phonon interaction, arising from a Jahn-Teller splitting of the outer Mn d-level, plays a crucial role in the system's behavior. They suggest that this mechanism significantly reduces electron hopping and affects the resistivity, leading to discrepancies in the calculated resistivity compared to experimental observations. The paper also discusses the implications of their findings for understanding the crossover between a high-temperature, polaron-dominated disordered regime and a low-temperature, metallic ordered regime. Experimental measurements of the spin wave stiffness are proposed as a way to verify or falsify their hypothesis.The paper by Millis, Littlewood, and Shraiman challenges the traditional "double exchange" model used to explain the resistivity of La1−xSr_xMnO_3. They present a solution to the double exchange model and show that it disagrees with experimental data in several important respects. The authors propose that a strong electron-phonon interaction, arising from a Jahn-Teller splitting of the outer Mn d-level, plays a crucial role in the system's behavior. They suggest that this mechanism significantly reduces electron hopping and affects the resistivity, leading to discrepancies in the calculated resistivity compared to experimental observations. The paper also discusses the implications of their findings for understanding the crossover between a high-temperature, polaron-dominated disordered regime and a low-temperature, metallic ordered regime. Experimental measurements of the spin wave stiffness are proposed as a way to verify or falsify their hypothesis.