I doubt cash will ever disappear, though. Even in the United States, about one-third of all transactions are still cash.

Beyond your job, what tech product are you currently obsessed with using in your daily life?

Air purifiers!

Like China, India has a big problem with air pollution in its major cities. Unlike China, the government is doing very little to address the problem.

In New Delhi, the nation’s capital, the wintertime air is so bad that its chief minister called it a “gas chamber.” In Mumbai, which is on the coast and gets nice ocean breezes, the air tends to be better. But by World Health Organization standards, the level of tiny particles in the air is still unhealthy, especially in the mornings. And sometimes it’s downright toxic.

So we run Swiss-made IQAir purifiers for at least part of every day.

Our 2-year-old is obsessed with FaceTime on our iPhones. She loves to call her grandparents in New York and carry the phone around the apartment, giving them a prime view of our ceiling as she chatters away.