From air taxis to autonomous cars, business psychologist Patrick Planing explains why behavior change remains the hardest problem in innovation.

Re: "Not an easy feat", (PostBag, Dec 22) & "Four killed in US strike on 'narco-trafficking vessel'." (World, Dec 18).

New and revived rail routes will see global train travel evolve in the year ahead, from practical cross-border links to high-end luxury journeys designed to lure travelers off planes.

Shareholders are getting serious about sustainability. by Robert G. Eccles and Svetlana Klimenko Most corporate leaders understand that businesses have a key role to play in tackling urgent challenges ...