Analysis of information sources in references of the Wikipedia article "Modified Dietz method" in English language version.
Peter O. Dietz published his seminal work, Pension Funds: Measuring Investment Performance, in 1966. The Bank Administration Institute (BAI), a U.S.-based organization serving the financial services industry, subsequently formulated rate-of-return calculation guidelines based on Dietz's work.
A slightly improved version of this method is the day-weighted, or modified Dietz, method. This method adjusts the cash flow by a factor that corresponds to the amount of time between the cash flow and the beginning of the period.
One of these return calculation methods, the Modified Dietz method, is still the most common way of calculating periodic investment returns.