Tigard Education Association (Union) *fn1 is the exclusive bargaining representative under the Public Employee Collective Bargaining Act (PECBA) ORS 243.650 et seq for teachers employed by Tigard School District 23J (District). During negotiations for a new collective bargaining agreement among Union's proposals was one entitled "Workload which specified grade-by-grade class size limits. *fn2 District refused to bargain, contending that class size is not a mandatory subject of bargaining. Union filed a charge with the Employment Relations Board (ERB), alleging that District's refusal to bargain over the proposal was an unfair labor practice under ORS 243.672(1)(e). ERB held, contrary to one of its earlier decisions, that the proposal to limit the number of students assigned to each teacher addresses a matter that relates to and significantly affects a teacher's workload and, therefore, is a mandatory subject of bargaining on which District must bargain in good faith. District appeals, and we affirm.

Both a union and an employer must at the other's request bargain collectively with respect to employment relations. ORS 243.650(4); ORS 243.672(1); ORS 243.672(2)(b). The question is what subjects are matters concerning employment relations as defined in ORS 243.650(7):

"'Employment relations' includes but is not limited to matters concerning direct or indirect monetary benefits hours vacations sick leave grievance procedures and other conditions of employment." (Emphasis supplied.)

Because neither the subject of workload nor a proposal for class size is specifically identified in the statute the question becomes whether either is an "other condition of employment."

In Springfield Education Assn. v. School Dist. 290 Or 217 233 621 P2d 547 (1980) Court said:

"The wording of [ORS 243.650(7)] indicates that the legislature chose to define 'employment relations' by example[.] * * * The reference to 'other' such subjects was not a delegation to ERB to make different choices; rather it is in effect a direction to ERB to replicate the same choice by regarding as 'employment relations' only those subjects which embody the same characteristics as 'monetary benefits hours vacations sick leave grievance procedures ' and no others."

The question of whether any subject is like or unlike the listed matters is "one of interpretation not of discretion." 290 Or at 233.

District contends *fn3 that ERB erroneously interpreted ORS 243.650(7) requiring reversal. ORS 183.482(8)(a). Whether it erred depends on the meaning of Springfield and Portland Fire Fighters Assoc. v. City of Portland 305 Or 275 751 P2d 770 (1988). In attempting to carry out Springfield's mandate that "other conditions of employment" must embody the "same characteristics" as "monetary benefits hours vacations sick leave [and] grievance procedures ERB considered each of those subjects to determine what characteristics they had in common and concluded that each was a generic term that was generally applicable to all public employees. That is consistent with Springfield's mandate that other subjects be of like kind.

That interpretation is also consistent with Court's analysis in Portland Fire Fighters, where the city had refused to bargain over the union's proposal responding to the city's announcement that it would limit the number of fire fighters who were permitted to be on vacation at any given time. ERB had applied a balancing test resulting in its concluding that the terms of the proposal would have less effect on conditions of employment than they would have on management rights; therefore, it did not concern a condition of employment and was not a mandatory subject of collective bargaining. We affirmed. Portland Firefighters Assoc. v. City of Portland, 86 Or App 662, 740 P2d 228 (1987). In reversing, the Supreme Court pointed out that the subject of the proposal related to vacations, which is specifically identified in the statute as a matter concerning employment relations" and was therefore a subject for mandatory bargaining unless the union's proposal was a sham. Because ERB had not found it to be a sham the city was required to bargain on the proposal. There was no occasion for ERB to apply a "balancing test."

The balancing test that ERB has used to determine what subjects with the same characteristics as those identified in the statute are "other conditions of employment" is set out in IAFF Local 314 v. City of Salem Case No. C-61-83 7 PECBR 5819 5825 (1983):

"Where a subject generally has a greater effect on working conditions than on management's rights that subject is a condition of employment and is mandatory. Where a subject generally has a greater effect on management's rights than on working conditions that subject is not a condition of employment and is permissive." (Emphasis in original.)

That application of the balancing test was approved generally in Springfield Education Assn. v. School Dist. supra. *fn4 ERB however has incorrectly applied that balancing test to determine whether proposals are mandatory or permissive. In Portland Fire Fighters Assoc. Court pointed out that balancing was appropriate only in determining whether a subject was an "other condition of employment." 305 Or at 282.

Once ERB has concluded after applying the balancing test that an unenumerated subject is an "other condition of employment" within the meaning of ORS 243.650(7) no further balancing is appropriate because that subject must be treated the same as an enumerated subject and is therefore one for mandatory bargaining. *fn5 Workload has been determined by ERB by use of the balancing test to be an "other condition of employment" and thus a subject for mandatory bargaining. OPEU v. State of Oregon Case No. UP-64-87 10 PECBR 51 79 (1987).

Because the subject of Union's proposal here purports to be workload the question is whether characterizing the proposal that way is a sham. Merely characterizing a proposal as workload does not make workload the subject of the proposal. See Portland Fire Fighters Assoc. v. City of Portland supra 305 Or at 284. ERB found that the terms of the proposal in fact relate to workload. ERB put the question this way:

"The appropriate inquiry is whether the proposal addresses a matter concerning a condition of employment; i.e. does the number of students assigned to a teacher significantly affect that teacher's workload?"

As we understand Portland Fire Fighters the question is whether a proposal relates to a subject requiring bargaining not whether it "significantly affects" that subject which ERB posed as the question. Substantial evidence supports ERB's finding that the proposal significantly affects workload; a fortiori it relates to workload. Before negotiations Union had conducted a survey of District's teachers that showed that class size was the single most critical factor in determining workload. It determines the number of parent teacher conferences the number of papers to be graded and the hours spent on assistance to individual students all of which relate to workload. There was also testimony to support the survey's findings.

District also contends that ERB failed to give an adequate explanation for rejecting its earlier holding that class size was not a mandatory subject of bargaining. Springfield Educ. Assn. v. Springfield School Dist. Case No. C-278 1 PECBR 347 358 (1975). ERB has held that it "will not reapply the balancing test to previously-adjudicated bargaining subjects unless [it is] presented with a compelling reason to do so." OPEU v. State of Oregon 10 PECBR at 69. That is merely an application of ORS 183.482(8)(a)(B).

Actually ERB did not re-apply the balancing test in this case to conclude contrary to its precedent that class size relates to a mandatory subject of bargaining. It concluded rather that its earlier decision was incorrect given its understanding of the Supreme Court's decisions in Springfield and Portland Fire Fighters requiring a different interpretation of the statute:

Only subjects of general applicability to public employees may fall within the statutory phrase "other conditions of employment." The balancing test is only appropriate to determine whether a subject should be considered an "other condition of employment." ERB pointed out that class size as such is not of general applicability to public employees; therefore it could not be a subject requiring bargaining. ERB concluded that its earlier analysis was wrong because it had failed to determine whether the class size proposal related to a subject that is an "other condition of employment." Its use of the balancing test was therefore skewed. ERB's explanation of its refusal to follow its decision in Springfield Educ. Assn. v. Springfield School Dist. supra is sufficient. It explained we believe correctly why it changed its previous analysis.

Additionally District contends that ERB's interpretation of ORS 243.650(7) is inconsistent with legislative policy. In Portland Fire Fighters the court stated the legislative policy underlying ORS 243.650(7):

"If negotiation and mediation are to be effective means of resolving labor disputes the scope of the definition of those matters subject to mandatory negotiation and mediation must be broad enough to encompass all matters over which labor disputes are likely to arise." 305 Or at 283.

Not only is ERB's interpretation consistent with the policy of channeling potential disputes into the bargaining process it is also consistent with the analysis of the statute employed by the Supreme Court in Portland Fire Fighters and Springfield.

Finally District argues that ERB erred in stating that Portland Fire Fighters compels the result that it reached. As indicated we believe that that decision combined with Springfield Education Assn. v. School Dist. supra requires the interpretation of ORS 243.650(7) that ERB followed.

Affirmed.