## 4 Conclusions  
When South Korea develops a new city, the government has made a preliminary decision on one of two heating systems, IHS and DHS. Usually, the latter has been preferred to the former because the latter has more advantages for reducing energy use, mitigating air pollutant emissions and abating greenhouse gas emissions than the former. As a result, while a portion of IHS has been converted to DHS and DHS has been increasing recently, it is still unclear which system is desirable in terms of maximizing the national economic effects. DHS is known to be better than IHS in terms of energy efficiency, convenience benefits to the consumer, benefits of decentralized generation, the effect of reducing greenhouse gas emissions, the effect of mitigating air pollutant emissions, and the effect of abating particulate matters. However, the IHS industry opposes DHS and the criticism is that expanding DHS will ultimately have a negative impact on the economy. More specifically, the main reason for opposing the expansion of DHS is that it will shrink the IHS industry, reducing the nation's overall value-added and employment, and ultimately affect the economy adversely. Thus, this study intended to analyze and provide accurate information on the economic effects of the IHS and DHS sectors in order to respond appropriately to the debate. In particular, in order to answer the question about how much production or investment in the two sectors affects the production, value-added, and wages of other sectors and the national economy, this article applied the demand-driven model that is at the heart of an IO analysis using the recently published 2017 IO table, making the two sectors exogenous instead of endogenous. It was found that one dollar of production or investment in the DHS sector induced more production, value-added, and wages throughout the economy than that in the IHS sector. That is, when the same amount of investment or production is made in the IHS and DHS sectors, the economic effects of the DHS sector are greater than those for the IHS sector. This is an interesting discovery from this study. The government's DHS policy can be supported in terms of economic effects. As mentioned earlier, the aim of this paper was not to develop innovative methodologies or to present creative ideas, but to share South Korea's situation and provide evidence that can be used to choose between DHS and IHS. In other words, in the situation where IHS and DHS are at odds with each other in residential heating system, this paper tried to analyze quantitatively what each role of IHS and DHS is in terms of economic effects using an IO analysis. Since the methodology used in this study was developed long ago and its framework is well established to some extent, and the models specifically used here were demand-driven and supply-driven models that are well developed in the literature, the methodology and the models cannot be considered innovative. Nevertheless, the implications of this paper can be useful in three aspects. First, within the scope of the authors' knowledge, this is the first attempt in the literature at the direct comparison of the economic effects of IHS and DHS. Although quite a number of studies have applied IO analysis to energy issues, it is difficult to find a case in which IO analysis has been applied in comparing IHS and DHS. Second, this paper provided policy officials with basic data for making comprehensive decisions about IHS and DHS and supplied the general public with easy-to-understand quantitative information about the economic effects. Not only policy officials but also the general public have been demanding information that directly compares the economic effects of IHS and DHS, but so far this information has not been available. Third, other countries that may experience conflicts similar to those in South Korea may refer to the findings from this study. Furthermore, similar or opposite results can be obtained by performing the same analysis as the structure of this study.