Finally ,there is usually a lag of 9 to 12 months from the time the need for a rate change is recognized and the time it is granted. This regulatory lag results because public hearings must be conducted before a regulatory commission can approve a requested rate change. Since the members of the regulatory commissions are either political appointees or elected officials and are thus subject to possible and tend from consumer groups, they usually postpone a rate increase as long as possible and tend grant rate increases which are smaller than necessary. During inflationary periods, this leads to underinvestment in fixed assets and to the inefficiencies discussed above. To avoid these regulatory lags, rates are sometimes tied to fuel costs and are automatically adjusted as variable costs changes .However, most public utilities are now in the process of deregulation.