Private and societal costs have their origin in the classic and neo-classic era. The market,
based on private costs, ignores externalities, while actors fail to gain access to information
on societal costs, causing a gap. The best practice price (BPP), a sustainability metric, can
fill this information gap. Based on science and the weighted opinions of stakeholders, best
practices for basic production factors such as land, labor, and natural resources are identified
and their costs calculated. Producers can use these data to calculate the BPP of their
products. Besides the market price (the price to be paid), the BPP is mentioned on the
invoice and price tag as representing the costs of production according to the best practices.
The ratio of market price (MP) to the BPP ‒ the BP ratio (BPR) – makes comparison of
different products possible. Using the BPR, producers, public entities, and consumers can
set goals for sustainable production or consumption.