Part one of the thesis studies differential diagnosticity towards substantive extrinsic information available in the environment. This research tests the interaction between regulatory focus and availability of extrinsic-substantive information such as consensus information, on the range of acceptable price. Prior research on regulatory focus led us to two divergent predictions. Our findings lend support to the asymmetric-elaboration account. Under this account, only prevention-oriented consumers are likely to change their acceptable price range if combinations of favorable-and-unfavorable consensus information are available in the environment, while promotion-oriented consumers disregard such information. We find that this difference is due to the differences in the level of difficulty experienced in specifying acceptable price range across the two regulatory foci. Further, we also undertake random-parameters regression models that provide unique general findings. For example, we find that for promotion-oriented consumers it is their high-level product construal, while for prevention-oriented consumers it is their low-level product construal that influences their respective acceptable price ranges, irrespective of level of external information available. Theoretical and managerial implications are discussed.