1. According to an essay in The Economist (an international newsmagazine), "Children, just like cigarettes or cell phones, clearly impose an external cost on people who are near them. Anybody who has suffered a 12-hour airplane flight with a crying baby just in front of them will immediately agree. Here is a clear case of market failure." The essay goes on to point out that young babies actually travel for free on airplanes. According to the essay, "The solution is obvious."

Why is this a "clear case" of market failure? What is the "obvious" solution? How will that solve the problem?