Which of the following statements is incorrect?

(a) An empirical study finds that the introduction of EZ-Pass, which is an electronic toll collection system, reduced the incidences of premature birth to mothers living within 2 km of a toll plaza by about 10%.

(b) Edlin and Karaca-Mandic (2006) find a positive correlation between traffic density and auto insurance cost across American states. Their findings suggest that driving imposes an accident externalities on other drivers.

(c) Coasian Bargaining does not work well in achieving efficient outcomes when the consumption or production externalities involve a large number of parties.

(d) Chay and Greenstone (2005) find that the Clean Air Act Amendments had little impact on the house prices of nonattainment counties in the U.S. once they account for the national trend of house prices.