| 摘要 | ABSTRACT
1. Research Purpose and Summary
This study tries to analyze effects of a variety of energy tax reform, particularly focused on the electric sector, on the system marginal price (hereafter SMP), the electricity tariff, and the tax revenue. Furthermore we investigate the macro-economic impacts by using electricity tariff changes resulting from these energy tax reforms. And also, we examine the income redistribution impacts of various energy tax reforms throughout tax revenue changes of those tax reforms.
In order to analyze the impact of the energy tax reform, we set up a total of 11 kinds of different tax reform scenarios including the Individual Consumption Tax Act amended in July, 2014(ICTA of 2014) that decided to impose new excise tax on the coal for power generation. In Feb. 2014, Korean congress decided to levy a new excise tax on coal for power generation by average 18Won/kg, while lowered the excise tax rate on LNG from 60Won/kg to 42Won/kg for the purpose of tax neutrality. We designated the ��6th Power Supply and Demand Basic Plan�� as a reference scenario in this study. More specifically, the energy tax reform scenarios were designed as follows. The excise tax rate on coal was set to three kinds such as 18, 30, and 60Won/kg, and the rate on LNG set to 42 and 60Won/kg. We also considered excise tax on nuclear power generation by 5.75Won/kWh that implied the hidden costs of generating electricity from the nuclear power plant. This external costs were derived from ��2th National Energy Basic Plan�� established in Jan. 2014. Combining above excise tax rates of each fuel, we composed the eleven energy tax reform scenarios including the reference case.
In order to estimate the effects of various energy tax reform scenarios on SMP, electricity tariff and tax revenue, we used the engineering-based electric market simulator named M-Core model. This electric market simulator is capable of reflecting a national power grid system realistically. It is also able to estimate the long-term SMPs and fuel consumptions by generation types. In this paper, we first estimate the annual SMPs and fuel consumptions with respect to LNG and coal from 2014 to 2027 year. Then, we calculate the adjusted settlement price(adjusted electricity purchased costs by electricity wholesaler, i.e. KEPCO, which are considered as the proxy for the electric tariff in this study, and derive the total tax revenues on each scenario. Lastly, we capture the impacts of various energy tax reforms on electric tariff and tax revenue comparing to reference scenario. Consequently, we could deduce the electric tariff and tax revenue changes with respect to the reference case.
By using derived results from changes of electric tariff on each energy tax reform and the computable general equilibrium model(CGE), we estimate the macro-economic impact of the change of electric tariff for each energy tax reform scenario. In addition, combined with results from the change of tax revenue on each scenario and CGE model, we investigate the income redistribution impact of each energy tax reform without considering the tax neutrality.
In this study, we perform the sensitivity tests as follows. First, we re-estimate SMPs, electric tariffs, and tax revenues for the respective energy tax reform scenario when the construction period of new generators such as coal-fired and combined cycle is delayed. Second, we do the same process when the electricity demand simultaneously changes responding to varying the electric tariff. By doing so, we might solve one of the practical problem of establishing ��Electricity Supply and Demand Basic Plan�� which long-term electricity demand is assumed to be deterministic. We use the basic input data reported from ��6th Power Supply and Demand Basic Plan�� for simulating long-run electric grid system of Korea.
2. Results and Policy Suggestions
The main findings are summarized as follows. First of all, we describe the finding results of effects of energy tax reform on SMP and electricity tariff in turn. If the excise tax is imposed on coal, thus SMP and electricity tariff will also rise. When the excise tax on coal is imposed by 18Won/kg, SMP will rise by 13% compared to the reference scenario. When the tax rate rise by 30Won/kg, then SMP will increase by 22%. Likewise, when the tax rate on coal rise by 60Won/kg, SMP will increase by 43% compared to the reference case.
The effects of imposing tax on coal on electricity tariff are similar with ones of SMP. If the excise tax rate on coal is 18Won/kg on average, while the tax on LNG is reduced from 60Won/kg to 42Won/kg, electricity tariff will increase by 7.6% compared to the reference case. Likewise, if the tax rate on coal sets to 30Won/kg combined with 42Won/kg tax rate on LNG, then the electricity tariff will rise by 12.8% in 2026 year. In case of 60Won/kg tax rate on coal with 42Won/kg on LNG, the electric tariff will rise further by 25.0% in 2026 year compared to the reference case.
The results of the effect of taxing on nuclear power generation on the electric tariff reflecting the hidden costs such as the nuclear accident risk response costs and policy costs show that the tax on nuclear power generation will increase the tariff rate about 1.23 to 1.75 times higher compared to not taxing on nuclear power generation.
According to the estimating results of the tax revenue by energy tax reform scenario, the total tax revenues of a reference case might be 1,101.1 billion Won in 2014, 471.5 billion Won in 2027. The reason why the tax revenues continuously decrease is that the electric generation mix would change in the long-run causing the capacity factor of the combined cycle generator decline sharply. In case of ICTA of 2014, the tax revenues will be 2,018.0 billion Won in 2014, 2,224.3 billion Won in 2019, and 1,756.7 billion Won in 2027. Namely, the government might collect more energy tax revenues 1 trillion Won to 1.7 trillion Won after ICTA of 2014. When the government imposes a tax of up to 5.75Won/kWh for nuclear power generation, the revenues could increase by 1.5 trillion Won compared to when the government do not impose a tax on it in 2027.
These estimated results might be understated and are likely to increase in the long-run because there exits various uncertainty such as the policy changes of generation mix, power demand fluctuations, environmental policy changes, grid construction and power plant construction delays and so forth. Depending on a variety of uncertainty variables, the potential tax revenues will increase further.
The impacts of the energy tax changes on macroeconomic might be somewhat negative. If the tax rate enacted this year(ICTA of 2014) is lasting, GDP could decrease by 0.03% compared to the reference scenario in 2014, and the decline will be further expanded by 0.26% in 2027. In the short-run, the nominal income level would be also reduced and the effect will be expanded further in the longer run. By income quintiles, the income of first income quintile would reduce the most and higher the income, income reduction rate would be trimmed. Therefore, the impact of the energy tax reform could be negative in terms of income redistribution. According to the estimates of Gini coefficient, ICTA of 2014 could aggravate the income redistribution from 0.3815 to 0.3818. These negative consequence for the macroeconomic indicators and income redistribution is deemed to have occurred because we do not assume the tax neutrality in this study.
Comprehensively considering the analysis results derived from this study, we may suggest several policy implications. Firstly, ICTA of 2014 could help slowing down the electricity dependent phenomenon that appears recently in Korea by increasing the electricity tariff.
Secondly, the excise tax on coal of 18Won/kg from ICTA of 2014 might be not enough to blunt the electricity dependent phenomenon. Since the purpose of imposing tax on coal is for internalizing the external effects such as pollution price, the tax rate on coal (current tax rate is 18Won/kg on average) should be higher than one on LNG (42Won/kg). Therefore in the long term, it is necessary to adjust upward the tax rate on coal. However, the effort to estimate accurate external costs including the nuclear power generation should be preceded in the process of future tax reform discussions.
Thirdly, if the social consensus for imposing tax on nuclear power has come to form, then we will need a sufficient and prudent discussion. We should carefully consider whether the form of tax is valid or whether the form of levy is more appropriate. In author��s opinion, the way of imposing the levy instead of tax on nuclear power might be more reasonable because the hidden costs derived from nuclear power such as the severe accident response costs occur in the unspecified point, but not occurring annually.
Lastly, since the energy tax reform could bring about a regressive income redistribution, we need to resolve these negative effects on macroeconomic and income redistribution through the income support or relaxation of other tax sources by using tax revenues collecting from the tax reform.
Unlike previous studies, this study comprehensively analyze the long term electricity market and macroeconomic impacts of the various energy tax reforms reflecting the realistic country��s electricity market operations and systems by using engineering based simulation model. Consequently, the simulating results might be more reliable and credible compared to previous studies�� conclusion. Thus we think that this is the most important contribution and differentiation of this study. Unfortunately, we are not able to control several uncertain variables such as the power plant and grid construction delays, renewable energy and greenhouse gas reduction policy, nuclear power plant construction and life extension policy direction, and power supply and demand policy, and energy and environmental policy conditions etc. In a further research, these limitations may have to be dealt with sufficiently. |
