2011 ORS § 657.025¹
(1) As used in this chapter, unless the context requires otherwise, employer means any employing unit which employs one or more individuals in an employment subject to this chapter in each of 18 separate weeks during any calendar year, or in which the employing units total payroll during any calendar quarter amounts to $1,000 or more.
(2) Whenever any helper, assistant or employee of an employer engages any other person in the work that the helper, assistant or employee is doing for the employer, with the employers actual, constructive or implied knowledge, the employer shall, for all purposes of this chapter, be deemed the employer of the other person, whether the other person is paid by the helper, assistant or employee or by the employer. All persons employed by an employer in all of the employers several places of employment maintained within the state shall be treated as employed by a single employer for the purposes of this chapter. [Amended by 1953 c.494 §1; 1955 c.655 §2; 1959 c.405 §1; 1971 c.463 §2; 1973 c.300 §1; 1975 c.257 §1; 1981 c.77 §1; 2007 c.46 §1]