Be rare and valuable.

David Oris was a late starter. 

Unlike his contemporaries in the Chicago Symphony Orchestra - who began at half his age - he didn't pick up a cello until he was 10 years old. At the elite level, it’s not just a matter of taking lessons over a long period of time. The successful instrumentalists practice an average of six hours each day, every day. Few people know what it means to have that kind of dedication, attention to detail, concentration, and discipline over the course of fifteen, twenty or twenty-five years. And that is before they get a job.

A cellist who starts the instrument at five years of age will very likely study and practice that instrument for twenty years or more before getting a job in a great orchestra. That’s over forty thousand hours of practice. At 42, David is an elite cellist. He continually trains hard to maintain his position. He now earns $150,000 per year, which is remuneration he can expect to maintain for several decades.

George Gershwin, by contrast, also started late. 

He had no interest in music until he was 10 years old - much like David - and only then, began learning piano with intent. Gershwin similarly poured himself into practice. Gruelling, daily, disciplined, practice. But Gershwin did something different - he also began composing his own music.

At first, his music was unremarkable: he earned 50 cents for publishing his first song "When You Want 'Em, You Can't Get 'Em". But by the time of his death at age 38 - one year younger than David being admitted to the Chicago Symphonic - he had amassed a small fortune. His estate had $26m of assets (adjusted for inflation).

The point is: the degree to which you are well paid in your career is proportional to how rare and valuable the thing it is that you contribute or create - not just to the hours and energy you put in. Talent, dedication, discipline are prerequisites - the nexus of rare and valuable is the key.

Basic economic theory tells us that if you want something that’s both rare and valuable - a great job that earns you millions of dollars - you need something rare and valuable to trade in return. George Gershwin's song "Rhapsody in Blue" is rare (it's unique) and valuable (on account of its high popularity). David Oris' playing of "Rhapsody in Blue" as part of the Chicago Symphony Orchestra is neither (relatively speaking).

A successful career requires the pursuit of something rare and valuable, and then the protection of that something with a career moat. Just like a product, where excessive supply without reciprocal demand will push down its value, so too will your career prospects be curtailed if what you do and create can be easily imitated, replicated or replaced.

When I was 18, I was already an accomplished C++ and Java programmer - a rare and valuable skill in 1998. Today, there are millions of accomplished programmers. By the time my son is 18, programming will be ubiquitous. Defining a successful career by that alone may be challenging.

Careers are competitive. You discover something good. Something valuable. Some way to make money or create value. The more you do it, the more you attract others. People learn of your discovery. They being to appear in increasing numbers, eager to get their piece of the good thing. The more people that appear, the more the good thing becomes less good. Eventually, it's crowded. It is a super-competitive space, and everyone only gets a little bit of it. The competition eventually stabilises, with the good thing shared amongst the victors. Life returns to being brutish and hard.

In the language of careers: a moat maintains your high employability in the job market, even when faced with stiff competition from others. Moats are rarely permanent. They must be maintained. 

A career moat consists of rare and valuable skills. The valuable property is what makes you highly employable. The rareness of the skill is what makes it a moat.