The cross-section for production of the N2+ B2&Sgr;u+ state by electron impact on N2 is one of the most important cross-sections for aeronomy because of the prominence of the N2+ first negative (0,0) band (B2&Sgr;u+←X2&Sgr;g+,&lgr;3914 ¿) in the dayglow and aurora. Recently developed electron-electron coincidence experiments have made possible the measurement of the branching ratios for ionization-excitation of N2 by electron impact at the 100-eV maximum of the cross-section. The N2 total ionization cross-section, measured in other experiments, can then be used to calculate the cross-section for production of the N2+ B2&Sgr;u+ state at 100-eV. Photoionization partial cross-sections and branching ratios from high-energy electron impact experiments are used to calculate the N2+ B2&Sgr;u+ cross-section at 2000-eV. The 100- and 2000-eV results are compared with cross-sections from electron impact optical emission experiments at the same incident energies. The cross-sections from electron impact and photoionization experiments are 30% smaller than the optical emission cross-section of Borst and Zipf at both 100-eV and 2000-eV incident energies but within 20% of the results of the most recent optical measurement at 100-eV. A value of 14.8¿10-18 cm2 for the N2+ B2&Sgr;u+ first negative (0,0) band cross-section maximum at 100-eV is within the error bars for all the experimental measurements except one.¿ 1996 American Geophysical Union