MFLINKS is now accessible on Wharton Research Data Services (WRDS).
Description from WRDS:
“MFLINKS provide a reliable means to join the mutual fund performance and expense information in the CRSP Mutual Fund Database (MFDB) with the equity holdings information in the Thomson-Reuters Mutual Fund ownership database (TFN/CDA S12). MFLINKS allows a researcher to gather details on holdings for either particular funds or fund families and groups of funds at specific points in time. MFLINKS has been developed with Professor Russ Wermers from the University of Maryland’s Robert H. Smith School of Business, as a contributor and ongoing consultant to the project. Professor Wermers was one of the first researchers to use linked mutual fund data. A good example of how MFLINKS can be used is his article, “Mutual Fund Performance: An Empirical Decomposition into Stock-Picking Talent, Style, Transactions Costs, and Expenses” (Journal of Finance, 2000). It decomposes mutual fund performance into its various components based upon actual holdings.
MFLINKS provides links between the 98% of the domestic equity funds in CRSP and Thomson-Reuters. The database consists of two tables that provide the mapping between CRSP and Thomson-Reuters mutual fund identifiers, to a common Wharton Financial Institution Center Number (WFICN), which is a unique and permanent fund portfolio identifier. There are 23,340 WFICN-CRSP_FUNDNO pairs in MFLINKS Table 1, including 4,600+ new links added in the 2013 update. There are 8,476 FUNDNO-WFICN pairs in MFLINKS Table 2, including 1,850 new links added in the 2013 update.”