Plot of redshift‐corrected burst peak luminosities, ﹩L_{\mathrm{pk}\,}﹩, vs. redshift‐corrected observed jet‐break times ﹩\tau _{j}\equiv t_{j}/ ( 1+z) ﹩. Jet‐break times ﹩t_{j}﹩ are from Frail et al. (2001), and luminosities are calculated from Jimenez et al. (2001). Because GRB 971214 only has a lower limit on the jet‐break time, it is not included in the fit (given by eq. [2]).