When John G. Roberts Jr. was named to the Supreme Court, he had a net worth of more than $6 million, accumulated during his lucrative years in private practice. When Samuel A. Alito Jr. was appointed, he had a net worth of more than $2 million, even though he had spent his entire professional career either in government or on the bench.

So how is it that Judge Sonia Sotomayor, nominated by President Obama to follow those two men onto the nation’s highest court, reported a net worth of just $740,000 this week, with no stocks or bonds and a savings account of $31,985, just marginally more than she owes her dentist and credit card companies?

To start with, although Judge Sotomayor became a partner during her eight years at the New York law firm Pavia & Harcourt before becoming a federal district judge in 1992, her salary in her final year at the firm was $151,761, a far cry from the $776,000 that Justice Roberts reported pulling down in his last full year at the Washington-based law firm Hogan & Hartson.

Between her salary as a circuit court judge and the money she made as a lecturer at Columbia University Law School, Judge Sotomayor made $205,330 last year. Still, the judge, divorced and with no children, does live in Greenwich Village, one of the more expensive neighborhoods in perhaps the most expensive city in the country. Just parking a car here  she drives a white Saab convertible  can cost hundreds of dollars a month.