TSP officials traditionally have been cool to the idea of adding funds that focus on particular markets—for example, a bill in the last Congress that made no progress would have authorized a precious metals fund–arguing that the broad-based C, S and I funds offer investors greater diversification and less potential exposure to losses from one economic sector performing especially poorly. Other issues include a concern about the higher administrative expenses of more narrow funds, the problem of choosing which of the numerous sector indexes to put in the TSP, and the risk of a perception that the government, by making only some sector funds available to its employees, would be favoring certain economic sectors. Largely for those reasons, Congress traditionally has deferred to the TSP in deciding which funds to offer. However, the REIT fund idea has the important backing of Reps. Rob Porter, R-Nev. and Tom Davis, R-Va., the chairmen of the federal workforce subcommittee and of the full House Government Reform Committee.