Suppose local govt decides that a tax is the best way to address the inefficiency created by outdoor concerts. Assuming the social cost curve and the private cost curve are parallel to each other, how much does the tax on concerts have to be to achieve the socially optimal outcome?

To determine the tax rate needed to achieve the socially optimal outcome in addressing the inefficiency created by outdoor concerts, we need to understand the concept of externalities and how they relate to the social cost curve and the private cost curve.

1. Define the externalities: In this scenario, the inefficiency created by outdoor concerts refers to the negative externalities associated with them. Externalities are costs or benefits that are not reflected in the market price of a good or service and are imposed on or accrued to parties outside of the transaction.

2. Understand the social cost curve and private cost curve: The social cost curve represents the total costs incurred by society, including the private costs and the external costs imposed on third parties due to the negative externalities. On the other hand, the private cost curve represents the costs incurred by the producers and consumers directly involved in the transaction.

3. Identify the socially optimal outcome: The socially optimal outcome occurs when the total social cost is minimized. It is the point where the marginal social cost equals the marginal social benefit, taking into account the negative externalities.

4. Determine the tax required: To address the inefficiency created by outdoor concerts, a tax is imposed to internalize the external costs and align the private and social costs. The tax should be set at a level that equalizes the marginal social cost with the marginal social benefit.

In this case, since the social cost curve and private cost curve are parallel, it implies that the external costs remain constant regardless of the quantity produced. Therefore, the tax should be set equal to the height or the vertical distance between the two curves.

To calculate the exact amount of the tax needed to achieve the socially optimal outcome, you would need additional information such as the equations or data points of the social cost curve and private cost curve. With those specifics, you can determine the tax rate necessary to internalize the external costs and align the private and social costs.

Keep in mind that this explanation provides a general framework for understanding the concept of taxes to address externalities. The actual determination of the tax rate requires more detailed information and analysis.