Interventionist Supply-Side Policies

Unlike market-based policies that aim to improve efficiency by removing the government from markets, interventionist policies aim for the opposite: Ensure market imperfections are fixed by the government. There are a few ways it can do so.

1. Facilitate education and training: By improving education levels of the population, new skills can be acquired and people can work better and more productive jobs. This is especially effective in developing countries.

2. Improve quality, quantity, and access to healthcare: This will solve many preventable labor-related problems.

3. Encourage research and development: By handing out grants, etc., more R&D can be done which improved productivity. This may also increase aggregate demand as more money is injected into the economy (jobs, new machinery, etc.)

4. Provide infrastructure: If the government provides water, electricity, internet services, etc., companies don't have to worry about that, and can rather focus on their specializations. Provisions such as highways and rail networks allow for greater efficiency.

5. Implement industrial policies: Give tax cuts or grants to a certain industry so it can develop more, creating more supply. 

So unlike the market-based policies, these believe more government intervention is needed to fix market failures rather than less. Both types of policies are acceptable to explain on exams, but beware of mixing the two: It wouldn't really make sense to suggest the government should provide infrastructure (interventionist) and at the same time privatize its infrastructure businesses (market-based)...