Where does wealth cluster? Primary locations are major world metropolises and to a lesser extent remote, pristine sparsely inhabited areas. Why? Shared beliefs and values (ethnic heritage, religion, language, politics), geographic desirability (climate, safety, airports), and resources (education, health care, jobs) help provide the answer.
Is wealth the end result of luck, toil, education or some combination? If we assume it is of some combination, then naturally our initial question of what causes wealth clustering is really a question of why geographically wealth has (re)located itself in a particular area. Furthermore, is it "earned" wealth, inherited wealth, budding wealth, or some combination of that rule set? Oddly enough, they are all usually in proximity!
This proximity derives from the inherent advantages of being close to the prize; there is a reason that more promotions always come from the headquarters of an organization. HQ is a great place to be for an up and coming whippersnapper, these are areas of excellence often in more than one regard; from pure physical beauty to educational infrastructure to engineering know-how and even reputation plays a strong hand. (Consider the frequency Harvard is cited versus nearly any other university!)
Let's face it; everyone loves a winner, and by extension we like to be near winners; whether economically, socially, or politically. The reasons for wealth clustering are complex, but the proximity to excellence is nearly universal. How does this help us Invest Like A Farmer? Excellence is its own momentum, and something we as financial farmers want to replicate as our own personal brand. Sustained excellence becomes a self-fulfilling prophecy.