An ethylene-based polymer, e.g., LDPE, with a low dissipation factor is made by a process comprising the step of contacting at polymerization conditions ethylene and, optionally, one or more comonomers, e.g., an alpha-olefin, with at least one carbon-carbon (C—C) hydrocarbyl, free-radical initiator of Structure 1: wherein R1, R2, R3, R4, R5 and R6, are each, independently, hydrogen or a hydrocarbyl group and wherein, optionally, two or more R groups (R1, R2, R3, R4, R5 and R6) form a ring structure, with the provisos that at least one of R2 and R5, and at least one of R3 and R6 is a hydrocarbyl group of at least two carbon atoms, e.g., an alkaryl of at least seven carbon atoms.