This sort of after-the-fact statistical analysis seems to be in vogue, at least since the 2008 publication of Outliers, Malcolm Gladwell's book that suggested the revolutionary notion that success is a combination of luck and hard work. In this controversial work, Gladwell seemingly reduced human accomplishment to a mix of being born at the right time, living in the right place, and spending 10,000 hours practicing one's profession. In the process, he also managed to annoy numerous readers who found the book a self-serving autobiography that ignored conflicting evidence and offered little useful information.

To Greenberg's credit, he ties his analysis to a tangible measure -- the Forbes list -- which keeps him from spiraling into the cherry-picked arcana method that Gladwell seems to prefer. Admittedly, some of Greenberg's most surprising conclusions seem to melt under the light of serious analysis. For example, his conclusion about Autumn births seems a little more obvious when one considers that September has more births than any other month. Thus, while it probably produces more billionaires than any other month, it also is likely to produce more paupers. Similarly, Greenberg's determination that Forbes 400 members tend to be good at math seems to be on a par with the conclusion that Pulitzer Prize winners are skilled wordsmiths.

Greenberg's revelation that 14 percent of the self-made tycoons on the Forbes 400 didn't graduate from college is shocking. On the other hand, its worth noting that college still seems to be a superior route to fame and fortune: Half of the tycoons who made their money in finance have graduate degrees, and 70 percent of the list's MBA holders graduated from Harvard, Columbia or Penn's Wharton School of Business.

Many belonged to Skull and Bones, Yale's super-secret club that boasts George H.W. Bush, George W. Bush and CIA chief James Jesus Angleton among its members. Unsurprisingly, success still seems to have a lot to do with who you know.

Speaking of boys clubs, what about the Goldman Sachs connection? As Greenberg notes, "At least 11 current and recent billionaire financiers worked at Goldman or one of its subsidiaries early in their careers." Of course, as Hank Paulson, Josh Bolton, Jon Corzine, Jim Cramer, and Robert Rubin could all attest, Goldman Sachs is a great name to have on one's resume.

While Greenberg seems to present a few useful tidbits for readers -- for example, if one wishes to spawn a billionaire, it's not a bad idea to conceive in January, February or March -- he also seems to ignore a few of the most pressing questions raised by the Forbes list. To begin with, how many of the list's self-made billionaires are men? How many were born in the United States? How many have bank accounts in the Caribbean? How many have used political connections for financial gain? How many are friends with Hank Paulson?

Inquiring minds want to know.