Although both III-N laser diodes (LDs) and LEDs employ electron blocking layers (EBLs) to reduce electron leakage from the active region, LDs typically operate at far higher current densities than LEDs. Shortcomings of the common rectangular EBL are discussed. Two alternative EBL designs have been systematically studied using numerical simulation: the inversetapered EBL and the inverse-tapered step-graded EBL. It is shown that the efficacy of each of these EBL designs depends strongly on the operational current density, suggesting that the EBL design considerations for III-N LDs and LEDs are fundamentally different.