# Effective rate of protection

In economics, the effective rate of protection (ERP) is a measure of the total effect of the entire tariff structure on the value added per unit of output in each industry, when both intermediate and final goods are imported. This statistic is used by economists to measure the real amount of protection afforded to a particular industry by import duties, tariffs or other trade restrictions.

## Explanation

Consider a simple case, there is a tradable good (shoes) that uses one tradable input to produce (leather). Both shoes and leather are imported into the home country. Suppose that in the absence of any tariffs, shoes use $100 worth of leather to make, and shoes sell for$150 in the international markets. Shoemakers around the world add $50 of value. If the home country imposes a 20% tariff on shoes, but no tariff on leather, shoes would sell for$180 in the home country, and the value added for the domestic shoe maker would increase by $30, from$50 to \$80. The domestic shoe maker is afforded a 60% effective rate of protection per dollar of value added.

This equals $(VA$d/$VA$int) - $1$, where:

An alternative that yields an identical answer is that the effective rate of protection equals $(T$f $- T$i)$/VA$int, where: