With this type of externality, in the absence of government intervention, the market equilibrium quantity produced will be less than the socially optimal quantity. Which of the following generate the type of externality previously described? Check all that apply. The local airport has doubled the number of runways, causing additional noise pollution for the surrounding residents. Your roommate Kate has bought a cat to which you are allergic. A leading software company has decided to increase its research budget for inventing new open-source technologies. Becky has planted hundreds of flowers in her front yard, beautifying the neighborhood both for herself and for her neighbors