Stark effect detected in high Balmer lines emitted from flares, prominences, and quiet chromosphere is generally interpreted as pressure broadening in a plasma of relatively high density. But a recent study of post-flare loops indicates that the densities of order 1012 cm−3 required to explain the observed Balmer line broadening are an order of magnitude higher than values derived using other plasma diagnostics such as Thomson scattering and Balmer line emission measures (Foukal, Miller, and Gilliam 1983). The disagreement might be explained as the difference expected between the true local density (measured by the Stark effect) in the obviously inhomogeneous loop plasma, and the straight mean or root mean square densities measured by Thomson scattering and line emission measures. More interestingly, the disagreement might imply a macroscopic electric field generated by, e.g., plasma waves in coronal magnetic loops.