What is the primary effect of implementing a per-unit tax on a good like copper in a market with negative externalities?

Implementing a per-unit tax on a good like copper aims to reduce negative externalities, which are the harmful effects that arise from production or consumption that affect third parties. When a tax is placed on copper, it raises the cost of producing and buying it, encouraging producers to reduce output and consumers to buy less. This decrease in production can lead to less pollution and other negative impacts associated with copper mining and processing. For example, if a copper mine is taxed, the company might invest in cleaner technologies to lessen its environmental impact or cut back on how much copper it produces. Ultimately, the tax helps align the private costs of production with the social costs, leading to a healthier environment and better resource management.