And car-pooling has a long history although my sense is that it&#x27;s perhaps less common than it used to be--probably because work hours tend to be more variable than in the past. While apps and so forth <i>can</i> reduce transaction friction enough to create markets where they didn&#x27;t previously exist, I reserve the right to be suspicious of claims that an app suddenly makes a service viable that wasn&#x27;t before.