It shall be the duty of the arbitrators to make written findings of fact and to render a written decision and order upon the issues presented in the case. In making its findings the board shall consider only the issues raised by the offers furnished to the mediator, as provided in section 7 of this act,¹ and shall not include any matter which is not regularly and customarily included as a matter for collective bargaining in the particular business. The arbitrators shall consider only the evidence submitted by the parties to the dispute. When a valid contract is in effect, defining the rights, duties and liabilities of the parties with respect to any matter in dispute, the board shall have power only to determine the proper interpretation and application of the contract involved. Where there is no contract between the parties, or where there is a contract, but the parties have begun negotiations, looking to a new contract or amendments of the existing contract and wage rates or other conditions of employment under the proposed new or amended contract are in dispute, the board shall consider all pertinent factors and shall establish rates of pay and conditions of employment comparable to prevalent wage rates paid and conditions of employment maintained for the same or similar work of workers exhibiting like or similar skills under the same or similar working conditions by public utility employers in the same business, if any, in the same labor market area, and if none in an adjoining labor market area within the Commonwealth of Pennsylvania, and which in addition thereto bear a generally comparable relationship to wage rates paid and conditions of employment maintained by all other employers in the same labor market area.

The board shall determine in each case from the evidence presented what constitutes in a particular case the same labor market area or an adjoining labor market area.

In establishing wage rates the board shall take into consideration the over-all compensation presently received by the employes, having regard not only to wages for time actually worked, but also to wages for time not worked including vacations, holidays and other excused time, and all benefits received including insurance and pensions and the continuity and stability of employment enjoyed by the employes.