In a market experiencing positive externalities, it is accurate to say that government intervention through subsidies is unnecessary because the private sector will naturally increase production to meet the social optimal level.

In a market with positive externalities, such as education or vaccinations, the benefits to society are greater than the benefits received by the individual consumers. This means that private companies may not produce enough of these goods because they do not see the full value of their contributions. Therefore, it's not accurate to say that government intervention through subsidies is unnecessary. In fact, subsidies can encourage more production and help align private incentives with social benefits, leading to a better outcome for everyone. For example, if the government provides subsidies for solar panels, it can increase their production and use, benefiting both the environment and the economy.