Carbon-Tax Benchmark as a Complement to Emissions Trading: An Empirical Calibration Based on Slovak EU ETS Data

This article examines whether a carbon-tax benchmark calibrated on EU ETS data can complement emissions trading in the Slovak Republic. Using Slovak EU ETS installation-level data on allocated allowances, verified emissions and EUA prices for 2015–2024, it develops an illustrative calibration methodology and compares the resulting tax yield with a modelled above-allocation ETS compliance-cost proxy. The comparison is intentionally limited: it cannot establish fiscal superiority over the EU ETS, because auction revenues, private compliance costs and potential tax revenues are conceptually different. The results show that, when the minimum tax floor is not binding, the tax yield is mechanically linked to the ETS proxy through the calibration coefficient. The estimated revenue difference should therefore be interpreted as a consequence of the benchmark design. The article also discusses distributional implications and CBAM compatibility, emphasising product-level embedded-emissions data and coordination to avoid double charging.