Beyond borders: Estimating the marginal emission factor of electricity trade
提出一个稳健的计量框架，利用相邻市场的风电波动作为工具变量，准确估算德国跨境电力贸易的边际排放因子，发现出口主要由煤炭驱动，忽略贸易会导致显著估计偏差。
Previous research has largely overlooked electricity trade when estimating marginal emission factors (MEFs), despite its growing significance in Europe and beyond. This study introduces a robust and consistent econometric framework to accurately estimate the MEFs for trade, demand, and different supply technologies in a highly interconnected market. We use exogenous supply shocks (variations in wind electricity) in adjacent markets as an instrument for trade flows, which are endogenous to CO 2 emissions, to generate unbiased MEF estimates. Our analysis, applied to high-frequency and publicly accessible data from Germany, reveals that exports are predominantly driven by lignite and hard coal, leading to considerable additional emissions. We further demonstrate that disregarding trade or ignoring its reverse causality results in substantial estimation biases. Unbiased MEF estimates are essential for shaping informed and effective policy decisions aimed at mitigating the environmental impact of energy systems in interconnected markets. • Study of marginal emissions factor of Germany’s cross-border electricity trade. • Wind electricity in adjacent markets is used as an IV to address simultaneity bias. • Germany’s exports are mainly driven by coal: MEF of net exports is 0.94 tCO2/MWh. • Ignoring reverse causality or omitting trade results in significant estimation bias. • The findings matter for nation carbon accounts and urge international coordination.