; vacancies Each member shall be appointed for the life of the Commission, and a vacancy in the Commission shall be filled in the manner in which the original appointment was made. (d) Compensation (1) In general Members of the Commission shall serve without pay. (2) Prohibition on compensation of Federal employees Members of the Commission who are full-time officers or employees of the United States may not receive additional pay, allowances, or benefits by reason of their service on the Commission. (3) Travel expenses Each member shall receive travel expenses, including per diem in lieu of subsistence, in accordance with applicable provisions under subchapter I of chapter 57 of title 5, United States Code. 5. Operation and powers of the Commission (a) Co-Chairs The Commission shall have two co-chairs who shall be elected from the members of the Commission during the first meeting of the Commission. (b) Meetings The Commission shall meet not later than 30 days after the members of the Commission have been appointed, and at such times thereafter as the co-chairs shall determine. (c) Rules of procedure The co-chairs shall, with the approval of a majority of the members of the Commission, establish written rules of procedure for the Commission, which shall include a quorum requirement to conduct the business of the Commission. (d) Hearings The Commission may, for the purpose of carrying out this Act, hold hearings, sit and act at times and places, take testimony, and receive evidence as the Commission considers appropriate. (e) Obtaining official data The Commission may secure directly from any department or agency of the United States, including the Congressional Budget Office and the Government Accountability Office, any information or technical assistance necessary to enable the Commission to carry out this Act. Upon request of the co-chairs of the Commission, the head of that department or agency shall furnish that information or technical assistance to the Commission. (f) Contract authority To the extent or in