Unit cost of manufacturing a new product.

Unit cost of remanufacturing a used product into a new product

Unit cost of collecting and handling a returned unit

The return rate.

The scaling parameter.

Unit wholesale price of a new product.

Unit retail price of a new product.

The cost of green innovation investment parameter.

The demand of new products in the market, where

, a is the market size, t is the consumer environmental awareness, e is the products’ eco-friendly level and b is the elasticity of demand.