Dual-frame telephone surveys that sample from both landline and cell-phone frames have become common because the US population is increasingly abandoning landline phones. Designing a dual-frame telephone survey requires a decision on the sample allocation, and ultimately the allocation of respondents, from each of the two frames. The allocation of the sample to the two frames influences the unequal weighting effect (UWE), and consequently, the precision of estimates calculated from the survey data. The sample allocation also influences cost, since obtaining cell-phone respondents is often more expensive than obtaining landline respondents. In this paper, we present results that designers of dual-frame studies can use to determine an allocation of responders that optimizes the precision of the survey estimates for a given cost
