Cost pass-through in the retail electricity market: Vertically integrated versus independent retailers
利用新西兰2018至2023年340个电力计划的月度面板数据，估计了纵向一体化零售商和独立零售商在总成本、线路成本和发电成本上的传导率差异，发现一体化零售商对发电成本的传导率显著更低。
This paper estimates cost pass-through rates for retail electricity prices in New Zealand. The dataset comprises monthly panel data for 340 electricity plans from January 2018 to May 2023. We estimate not only the pass-through of total costs but also the pass-through for the two main components of total costs — the lines costs (transmission and distribution costs) and generation costs. The generation cost is measured using a wholesale market price of generation. First, we find that vertically integrated retailers have a lower pass-through rate (for total costs) than independent retailers. Second, the pass-through rate is lower for generation costs than for lines costs. These two results are related: whereas vertically integrated and independent retailers pass-through a similar fraction of their lines costs, independent retailers pass-through significantly more of their generation costs than vertically integrated retailers. Our findings suggest that vertically integrated retailers respond to generation costs very differently than independent retailers. This may be because, for vertically integrated retailers, wholesale market prices for generation are simply an opportunity cost, while for independent retailers it is an actual cost. Our findings motivate further theoretical work into the different responses of vertically integrated and independent retailers. • Vertically integrated retailers have relatively low pass-through rates. • Pass-through rates are lower for generation costs than lines costs. • Integrated and independent retailers pass-through similar fractions of lines cost. • Independent retailers pass-through significantly more of their generation cost.