RCW 70A.65.340 — Periodic economic modeling.

1. (1) The department shall periodically perform economic modeling for purposes of analyzing design features of the program created by this chapter. This analysis must include the following components:

   1. (a) A baseline model assuming implementation of complementary emission reduction measures; and
   2. (b) Additional modeling scenarios that department staff deem necessary, which must include current available technology and known adoption rates to better understand how to administer the program created by this chapter.
2. (2) Not later than December 31, 2026, the department must include a modeling scenario that reflects linkage with other jurisdictions.
3. (3) The department must post on its website the economic modeling results by December 31, 2026. The department must post updated economic modeling results by December 31, 2027, and by December 31st every two years thereafter.

4. (4) Economic modeling results posted by the department must contain:

   1. (a) An estimate of program benefits including the total social cost of carbon;
   2. (b) An estimate of the compliance cost for sectors regulated under this chapter;
   3. (c) The department's identification of program design features contributing towards achieving the emission reduction limits established in RCW 70A.45.020; and
   4. (d) A description of assumptions, policy decisions, and model design used in the baseline and each additional modeling scenario.

[ 2025 c 320 s 2.]