A high pressure polymerization process to form an ethylene-based polymer comprises the steps of: A. Injecting a first feed comprising a chain transfer agent system (CTA system) and ethylene into a first autoclave reactor zone operating at polymerization conditions to produce a first zone reaction product, the CTA system of the first reactor zone having a transfer activity Z1; and B. (1) Transferring at least part of the first zone reaction product to a second reactor zone selected from a second autoclave reactor zone or a tubular reactor zone and operating at polymerization conditions, and, optionally, (2) freshly injecting, a second feed into the second reactor zone to produce a second zone reaction product, with the proviso that at least one of the first reactor zone product and the freshly injected feed comprises a CTA system with a transfer activity of Z2; and with the proviso that the ratio of Z1:Z2 is greater than 1.