Besides promoting free trade, Turgot argued against taxes and tariffs. Due to the reciprocal nature of trade, Turgot pointed out the absurdity of wanting only to export while not importing. Protective tariffs, set up to discourage imports, were described as war of all against all using state monopoly privilege at the expense of consumers. They led to a system of reciprocal oppression between industries and a balance of annoyance and injustice which made everyone worse off.
Turgot also noted that taxes crippled commerce. Urban taxes distorted the location of towns and encouraged evasion of duties. Taxes on capital destroyed thrift and discouraged investments. Taxes on merchandise led to smuggling.
To minimize the distortion caused by taxation, Turgot advocated for a single tax on the product of land.
Reference
- Murray Rothbard, Economic Thought Before Adam Smith (1995), Chapter 14.