[jdietrich]

It's mostly about continuity of records and property rights. Most countries a) didn't have written records of ownership until relatively recently, b) had a collapse of government that led to the loss of records or c) had a revolution that involved mass confiscation or redistribution of property.

Japan, Germany and Switzerland have been efficient bureaucracies since time immemorial. They've had brief periods of trauma, but they haven't experienced an upheaval with the profound and lasting impact of something like the Russian revolution, the Great Leap Forward or the British Raj.

They are also cultures that highly value economic stability and family ownership, although I think this is a secondary factor. I have no doubt that there are huge numbers of family-owned businesses that would be on this list, but for the fact that no records exist to demonstrate their age.