Suppose that the state of Connecticut is attempting to set a water quality standard, where water quality is measured as the percent of mercury abated (A), and the marginal social benefit (MSB) and marginal social cost (MSC) of abatement have been estimated as follows:

MSB = 40 - 0.1A

MSC = 36 + 0.025A, 

The state’s department of environmental protection sets the standard at 20 percent. Is this standard set efficiently, too stringently, or too leniently? Explain briefly.