From the point of view of an individual investor, all that matters is whether he will get an adequate return on the investment he makes. If a city government decides to install a desalination plant, the investor’s primary concern is that someone (the government or those buying water) will pay enough money that he can make an adequate return on his investment over time. Citizens clearly need water. The only question is whether citizens can afford the desalinated water from their discretionary income. Obviously, if citizens spend more on desalinated water, the amount of discretionary income available for other goods will be reduced.
The same issue arises with pollution control equipment installed by a utility, or by an auto maker. The need for pollution control equipment arises because of limits we are reaching–too many people in too small a space, and too many waste products for the environment to handle. The utility or auto makers adds what is mandated, since clearly, buyers of electricity or of an automobile will recognize the need for clean air, and will be willing to use some of their discretionary income for pollution control equipment. Mandated renewable energy requirements are another way that governments attempt to compensate for limits we are reaching. These, too, tend to impose higher costs, and indirectly reduce consumers’ discretionary income.