  The energy spectra of ultra high energy cosmic rays reported by the AGASA,
Fly's Eye, Haverah Park, HiRes, and Yakutsk experiments are all shown to be in
agreement with each other for energies below 10^{20} eV (after small
adjustments, within the known uncertainties, of the absolute energy scales).
The data from HiRes, Fly's Eye, and Yakutsk are consistent with the expected
flux suppression above 5\times 10^{19} eV due to interactions of cosmic rays
with the cosmic microwave background, the Greisen-Zatsepin-Kuzmin (GZK)
"supression," and are inconsistent with a smooth extrapolation of the observed
cosmic ray energy spectrum to energies > 5\times 10^{19}$ eV. AGASA data show
an excess of events above 10^{20} eV, compared to the predicted GZK suppression
and to the flux measured by the other experiments.
