Benjamin Todd

Later in the guide, we'll discuss why we think these long-run effects could be vastly more important than just saving a billion lives from nuclear catastrophe.

Yet even with the lower estimate, Petrov's impact likely dwarfs that of Nahlen and Landsteiner.

What do these differences in impact mean for your career?

We've seen that some careers have had huge positive effects and some have vastly more than others.

Some component of this is due to luck.

The people mentioned above were in the right place at the right time, giving them the opportunity to have an impact that they might not have otherwise received.

You can't guarantee you'll make an important medical discovery.

But it wasn't all luck.

Landsteiner and Nahlen chose to use their medical knowledge to solve some of the most harmful health problems of their day, and it was foreseeable that someone high up in the Soviet military might have an opportunity to have a large impact by preventing conflict during the Cold War.

So what does this mean for you?

People often wonder how they can make a difference, but if some careers can result in thousands of times more impact than others, this isn't the right question.

Two different career options can both make a difference, but one could be dramatically better than the other.

Instead, the key question is, what are some of the best ways to make a difference?

In other words, what can you do to give yourself a chance of having one of the highest impact careers?

Because the highest impact careers achieve so much, a small increase in your chances means a great deal.

The examples above also show that the highest impact paths might not be the most obvious ones.

Being an officer in the Soviet military doesn't sound like the best career for a would-be altruist, but Petrov probably did more good than our most celebrated leaders, not to mention our most talented doctors.

Having a big impact might require doing something a little unconventional.

So how much impact can you have if you try, while still doing something personally rewarding?

It's not easy to have a big impact, but there's a lot you can do to increase your chances.