It is assumed that the QSOs are at cosmological distances as indicated by their emission-line redshifts. It is further assumed, as indicated by present evidence, that none of the 21 QSOs with emission-line redshifts, ze, of 2.0 ± 0.1 (or of the 30 with ze = 2.0 ± 0.2) is screened by an intervening normal galaxy. The simplest conclusion from these data is, then, that the screening probability must be less than 0.08 (or 0.06) at ze = 2.0. This, in turn, restricts allowable cosmological models in the (σ0, q0) diagram by providing lower limits for ß0 as a function of q0. One can also rank cosmological models in order of the probability that there be no screening of the 21 (or 30) objects. In either case the steady state model ranks higher than the general relativity models found by Peach to give the best fit in the (m – z) diagram.