The calculation of the net worth of L.A.? wealthiest residents is a lengthy and difficult task for the reporters and editors of the Business Journal. This year it was particularly challenging given the vast losses of wealth.

The paper starts by identifying candidates who appeared on past lists, almost made the list or who might be wealthy enough to make it. Knowing that some list members had been wiped out over the past year, the search for new candidates took on greater importance.

Individuals are sent a questionnaire asking for details on holdings in stock, property, investment and debt. Some billionaires politely deny our request, or even ask to be removed from our list. Others are responsive and provide detailed information on holdings ?some on the record, some off.

Business Journal reporters then go through a detailed process of identifying and valuing holdings for individuals. For those that disclose holdings, valuations are double-checked to make sure candidates are not overvaluing or undervaluing holdings.

Individuals who hold at least 5 percent of stock in public companies are required to disclose their holdings. For those who derive their wealth from privately held companies, estimates are made based on valuations of comparable public companies. We also rely on expert opinions from wealth managers, real estate brokers and others.

Once a net worth figure is calculated, reporters follow up with candidates to try to verify results. Many final numbers are as accurate as they can be when net worth is in the billions, but it can be difficult to obtain more than an estimate for a minority who have undisclosed private holdings and decline to cooperate.

The Wealthiest Angelenos are ranked by net worth in descending order. In the case of ties, the members are ranked alphabetically. Percentage changes in net worth reflect estimates prior to rounding. Prior year’s net worth is revised as noted when information changes earlier estimate. Stock price figures reflect data as of May 8.

The estimates were researched and compiled by Richard Clough, Deborah Crowe, Alexa Hyland, Daniel Miller, David Nusbaum, Charles Proctor and Joel Russell.