A) What are the key concepts of efficiency and causes of market failure? B) What are the actions that governments take to remedy market failure?

a. Efficient outcomes in trade promote the economy of a state, and it is only achieved if all the potential trade gains are exploited. One concept that upholds efficiency is; a trade is considered an efficient trade if the marginal cost doesn't surpass the marginal profit. Also, the government can alter individual decisions to change the market outcomes to match the efficiency rule.

Market failure can be a result of the following reasons; externalities where third parties have to pay consequences despite their indirect involvement. Public goods also influence market failure when a portion of consumers doesn't pay but keeps on using these goods as if they have paid. Imperfect market information about goods and sells risks market failure due to the misleading benefits and costs of products.

Governments can manage market failures by implementing legislative rules that curb the behaviors of market participants. Violation of these rules is punishable. They could also introduce price mechanisms to keep away harmful products from consumers by increasing their taxes.