The Impact of the Tokyo Emissions Trading Scheme on Office Buildings: What Factor Contributed to the Emission Reduction?

The Tokyo ETS is the first emission trading scheme to control GHG emissions from office buildings. Although the Tokyo government claimed that Tokyo ETS had been successful, some argued that the emission reduction under Tokyo ETS was actually the result of electric power price increases triggered by the Great East Japan Earthquake in 2011. Using a facility-level data set for Japanese office buildings, we conducted an econometric analysis to examine the impact of Tokyo ETS. We found that half of the emission reduction is a result of the ETS, while the rest of the reduction is due to the electricity power price increase. Another unique feature of Tokyo ETS is that an accurate permit price is not publicly available due to its design. Using our estimated model, we found that the price is approximately $50 per ton of CO2 in the early phase.

Carbon pricing has become a popular economic instrument used to help mitigate greenhouse gases (GHGs), which cause climate change. Among carbon pricing techniques, emission trading schemes (ETSs) have gained attention. Notably, the European Union Emissions Trading Scheme (EUETS) was the first comprehensive ETS to control carbon dioxide (CO2) emissions. In the US, the Regional Greenhouse Gas Initiative (RGGI) started in 2009, followed by the California system. Among Asian countries, Korea was the first to introduce a cap-and-trade scheme. Finally, China, the largest emitter of greenhouse gases (GHG), implemented seven regional ETSs in a pilot scheme and announced that it would introduce a national level ETS starting with the power sector (Duan, 2020).
The Japanese government has not yet adopted an ETS at the national level. The Tokyo metropolitan government, however, successfully introduced an ETS, the Tokyo Emissions Trading Scheme (Tokyo ETS), in 2010 (Arimura, 2015). This ETS is not only the first cap-and-trade ETS for CO2 emissions in Japan but also the first in Asia.
Furthermore, Tokyo ETS is unique among ETSs because the main target of this scheme is office buildings. Indeed, it is the first ETS to regulate GHG emissions from office buildings.
Tokyo ETS consists of several phases. Phase I started in 2010 and ended in 2014.
Phase II started in 2015 and implemented a more stringent emission target. At the start of Phase II of Tokyo ETS, the Tokyo metropolitan government reviewed the level of emissions from the regulated buildings and confirmed an emission reduction of 25%. 4 It is not clear, however, if the ETS is actually the driver of the emission reduction during this period.
One should note that Japan experienced the Great East Earthquake in 2011, which was followed by the nuclear accident in Fukushima. This nuclear accident affected electricity supply in Japan, but the shortage of electricity capacity was particularly severe in Tokyo because the nuclear power plants in Fukushima belong to the Tokyo Electric Power Company (TEPCO), which is almost a monopoly in supplying electricity to the Tokyo area. Due to the accident, TEPCO had to rely on expensive natural gas to generate electricity, and moreover, it had to compensate for the damages caused by the nuclear accident. This cost was passed TEPCO's consumers, and so power prices in the Tokyo area increased sharply after the earthquake. Some people, therefore, hypothesized that the reduction in GHG emissions in the Tokyo area was caused by the electricity price increase and not by the ETS. This hypothesis is supported by those who viewed EUETS with skepticism and thus doubt that an ETS could work in the real world, especially after seeing the low permit prices in EUETS.
In addition to the price increase in the electricity, other factors may have contributed to the emission reduction in Tokyo. For example, the Japanese government adopted a rolling blackout immediately after the accident. In this scheme, the power companies intentionally stop power supply to one area for a certain period and then shift to stop the power supply to another area while the supply for the first area returns. In this way, the power companies were able to balance the total amount of electricity supply and demand. It could be argued that the experience of the rolling blackout could have incentivized consumers to save energy to avoid future blackouts. This paper empirically investigates the effects of the Tokyo ETS to clarify the cause of emission reduction in Tokyo using facility-level panel data. By conducting a facilitylevel survey, we collected data on office buildings and university buildings in Japan. Our study is not the first to examine Tokyo ETS ex post. Roppongi et al. (2017) qualitatively reviewed the Tokyo ETS. Wakabayashi and Kimura (2018) conducted a quantitative expost analysis of Tokyo ETS with a combination of interviews and facility-level data analysis. However, this latter study suffers from omitted variable bias; notably, they ignored the influence of the power price increase on the GHG emissions from office buildings. This is the first study to examine the impact of Tokyo ETS on emissions by incorporating the impact of the power price increase.
This paper contributes to the empirical literature of ETSs. Until recently, researchers have focused on ex-ante analysis using a theoretical analysis or a computable general equilibrium analysis (e.g., Böhringer and Lange, 2005). Recently, however, researchers started to conduct ex-post analyses of ETS. For example, Martin et al. (2016) and Ellerman et al. (2016) reviewed the experience of EUETS. Others initiated ex-post econometric analyses as the ex-post data have become available. For example, Ellerman and Buchner (2008) and Anderson and Di Maria (2011) confirmed the effect of EU ETS on emission reductions in European countries under EU ETS in the first phase. Petrick and Wagner (2014) and Colmer et al. (2018) estimated not only the abatement effect of EU ETS but also its impact on some economic activities using a German and a French facility-level dataset. Calel and Dechezlepretre (2016) examined the impact of EUETS on innovation in European firms, measured with patents. RGGI, a regional ETS in the US, is also reviewed. Murray and Maniloff (2015) investigated why GHG emissions in RGGI states were reduced and examined the factors contributing to emission reduction in the region. Our study is in line with this stream of literature, but it is unique because we have examined the impact of ETS on office buildings. EUETS was designed for Electronic copy available at: https://ssrn.com/abstract=3487245 manufacturing facilities and power plants, and RGGI was designed for power plants, but Tokyo ETS was one of the first ETS focusing on office buildings.
One unique aspect of Tokyo ETS is that the financial sector plays a limited role. The Japanese industry association was against the introduction of ETSs, referring to it as a "casino (money game)" (Roppongi et al., 2017). They claimed that an ETS would invite speculation by financial companies, which would destroy its effectiveness. In response to this criticism, the Tokyo government created a unique design for its ETS: there is no auction or the exchange on the market where the price of the permit is made transparent.
Thus, the price of permits in Tokyo ETS is somewhat mysterious. The second contribution of this paper is to reveal the implicit price of the permit through the estimated models. This paper is constructed as follows. The next section reviews the basic design of Tokyo ETS. Section 3 explains the data, and the estimation results and the discussion are shown in section 4. Finally, section 5 concludes the paper.

Design of Tokyo ETS
The Tokyo metropolitan government established an emission target of a 25 percent reduction by 2020 from the 2000 level. Initially, they tried a voluntary scheme (Roppongi et al., 2017), but this did not lead to a substantial emission reduction. Thus, the Tokyo government decided to adopt a mandatory emission reduction scheme with flexibility, i.e., an ETS.
Tokyo ETS aims to mitigate the CO2 emissions from large-scale facilities in the commercial and manufacturing sectors. Facilities that consume 1,500 kiloliters of oil equivalent per year or more are regulated in this system 5 . The emissions from these facilities amounted to approximately 40 percent of total CO2 emissions from the commercial and manufacturing sector in Tokyo.
The Tokyo ETS was first announced in 2007. The first phase ran from 2010 to 2014 and the second phase is from 2015 to 2019. In the first phase, which is the target of our analysis, the mandatory CO2 reduction targets were 8 percent for commercial buildings Tokyo ETS is a mandatory scheme, and any facility that cannot attain the goal set by Tokyo ETS faces a fine. This contrasts with Saitama ETS, which was modeled after Tokyo ETS and introduced in 2011. Saitama ETS is a voluntary scheme and thus has no fines (Hamamoto, 2020).
A unique feature of Tokyo ETS is that it regulates office buildings as well as Korean ETS is manufacturing facilities (Oh, 2020,). Therefore, Tokyo ETS differed from other schemes in 2010 in that it regulated emissions from the service sector.
Though the Tokyo ETS is a regional ETS, there is a high number of regulated facilities. In the Tokyo area, all facilities consuming at least 1,500 kiloliters of oil equivalents per year are subject to Tokyo ETS; in 2013, for example, 1,392 facilities had to comply with the Tokyo ETS. The number of entities covered by the Korean ETS is approximately 600 (Oh, 2020, this issue). Thus, there is a high number of entities under the Tokyo ETS, although their total emissions are relatively low, at 12 million CO2-tons in 2017, which is less than the emissions covered in the Korean ETS.
Tokyo ETS is also unique in how it measures GHG emissions. The emission from the usage of electricity, , as indirect emissions, is regulated because the majority of emission from commercial and office buildings are from their electricity usage. This is different from other ETS such as EUETS which focuses on emissions from fossil fuel combustion.
The CO2 emissions from the electricity usage for facility are measured by multiplying its electricity consumption by the CO2 intensity. The CO2 emission intensity of electricity was 0.382 kg CO2 per kWh 6 and fixed for the compliance period under Tokyo ETS.
According to this method, the total emission under Tokyo ETS was approximately 11.8 million CO2 tons in 2010.
To mitigate the burden of compliance, the Tokyo ETS provides four types of domestic offset credits. The first is small-and medium-sized installation credits within the Tokyo area. Large regulated facilities can earn credits by investing in energy efficiency in unregulated small and medium size facilities. Second one is outside Tokyo Prefecture credits. Organizations in Tokyo can earn emission reduction credits if they reduce emissions outside of Tokyo. Third, firms can use Saitama credits, i.e., credits from Saitama ETS. Saitama ETS is modeled after Tokyo ETS, and thus, the features of the two systems are similar, and the credits from the two systems are exchangeable. Finally, Tokyo ETS accepts renewable energy certificates. Facilities can earn credits if they invest in renewable energy. International credits such as CDM credits, however, cannot be used to offset GHG emissions in this scheme.
Facilities under Tokyo ETS can achieve their target through several methods; Table   1 shows the compliance methods by entity. First, they can reduce emissions: according to the Tokyo metropolitan government, 91 percent of facilities reduced emissions beyond the target. Alternatively, they can achieve their target by obtaining additional credits: approximately 9 percent of facilities achieved the target through the acquisition of credits.
Permit trading under Tokyo ETS is regulated in a unique manner. When facing the adoption of an ETS, some stakeholders were afraid that permit trading under an ETS could create a "casino" (Ropponogi et al., 2017). The manufacturing sector criticized ETSs by claiming that these systems invite speculation by the financial sector and thus are not effective as an instrument for environmental policy. In response to this criticism, the Tokyo government allows only "reduction credits" and not "emission credits". That is, one can earn credits only after achieving emission reduction. Moreover, there is no auction of permits. Only emitting entities can participate in trading, and the financial sector does not play a crucial role in the system. Consequently, the trades have been bilateral in many cases, and the trading of permits was not very active compared to other markets.
The Tokyo government investigates the price through private interviews and publicizes the permit price; Figure 1 depicts the trajectory of permit prices. The price was initially approximately 10,000 JPY ($1,333) per CO2 ton in 2011, but it fell to approximately 4,500 JPY ($37) per CO2 ton in 2015 for reduction credits. These numbers are a reasonable conjecture but may not reflect the "true price" because the Tokyo metropolitan government does not reveal how it constructs prices. 7 It should be noted that the reduction credits are bankable, and so credits from Phase I can be used in Phase II. However, they can only be carried for one phase; credits from Phase I cannot be used in Phase III.

Data
We have obtained data from various sources as follows.

Dependent Variables and Other Facility-Level Data: Mail Survey
We chose the office building sector from among the regulated facilities for several reasons. First, under Tokyo ETS, office buildings represent the largest group among the commercial buildings. Hence, office buildings are the major target of regulations 8 .
Second, among the regulated facilities, office buildings are relatively less influences by economic fluctuations in terms of energy consumption.
We conducted a mail survey in 2015. We sent questionnaires to 824 owners of office buildings across Japan. The population of office buildings was chosen from the database, which was constructed based on the Act on the Promotion of Global Warming Countermeasures run by the Ministry of the Environment. Facilities that consume 1,500 of energy must report their GHG emissions every year. From this database, we were able to obtain a list of the address of all office buildings. We received 414 replies from the office buildings, representing a reasonably high response rate of 50.2 percent.
Office building owners were asked to report their CO2 emissions levels from 2009 to 2013; we also asked for electricity consumption and energy consumption, where energy consumption is the sum of electricity consumption and fossil fuel consumption.
Respondents were also asked to report the number of employees, the floor area, their experience with the rolling blackouts and any other requests for energy savings from the 8 There is only one fossil power plant, and there are a small number of manufacturing facilities in Tokyo.

Electricity Price
We collected data on electricity prices from a publicly available database of the   Saitama have an ETS in place. Therefore, we can disentangle the impact of the ETS from the increase in power prices.

Savings Requests & the Rolling Blackout
In addition to power prices and ETS, other factors may also influence emissions.The Great East Japan Earthquake in 2011 damaged a few power plants. Most notably, among them is the nuclear power plant in Fukushima. This led to the shutdown of major nuclear power plants.
Consequently, TEPCO faced a shortage of power supply. In response to this emergency, TEPCO introduced "rolling blackout". Under this system, TEPCO intentionally stopped the electricity supply to a designated area. After several hours, another area faced the intentional blackout. In this way, TEPCO managed to supply electricity to their customers with limited capacity. In our survey, we asked if they had experienced the rolling blackout.
Another important aspect is demand-side management. In response to the electricity crisis, the government introduced "request to reduce the electricity consumption". In our survey, we asked if the owners received this request.
We suspect that these experiences may have given incentives to save energy for consumers.
We construct a dummy variable, saving request/rolling blackout, which takes the value one if the building owners faced either the rolling blackout or the request of electricity consumption reduction. In our sample, 41 percent of facilities faced this request.

Vacancy Ratio of Office Buildings
The emissions from office buildings are influenced by economic activities conducted in each building. To capture the economic activities in the building sector, we use the vacancy rate of office buildings in each region as a proxy for the vacancy rates for a building. We exploit publicly available data from Miki Shoji Co., ltd. which provides information on the office market in seven large business regions in Japan: Sapporo, Sendai, Tokyo, Yokohama, Nagoya, Osaka and Fukuoka. Unfortunately, this dataset does not offer information on all prefectures separately. We then assigned values to the office buildings based on proximity.

Cooling Degree Days and Heating Degree Days
To control the impact of weather conditions, we include cooling degree days (CDD) and heating degree days (HDD). This information is publicly available from the Japan Meteorological Agency. We calculated the CDD and HDD for each prefecture.
Electronic copy available at: https://ssrn.com/abstract=3487245 3.6. CO2 Intensity  Table 2 illustrates the summary statistics. For some variables, we removed outliers from our analysis. Specifically, we excluded the top and bottom 1% of the distributions in the sample. The first panel of Table 2 shows summary statistics for office buildings.

Summary Statistics
On average, the annual CO2 emissions for an office building considering the total sample was 7,105 tons of CO2. The summary statistics for office buildings in Tokyo and other regions are shown in the second and third panels of Table 2. From these panels, we find that the annual CO2 emissions from office buildings in Tokyo was 7,463 tons of CO2, whole office buildings in other regions accounted for 6,918 tons of CO2. Hence, office buildings in Tokyo on average emit CO2 more than those in other regions. We also find large differences between buildings in Tokyo and other regions in terms of size. Generally, office buildings in Tokyo have greater floor area and more employees than office buildings in other regions.

Econometric Model
To quantify the impact of the ETS, we estimated the following equations for office buildings and universities.  Table 4 exhibits the estimation results from each of three models. Each model has two specifications. Models 1, 3, and 5 are base models, and models 2, 4, and 6 allow two possibilities to be examined: (1) the difference in effectiveness across years and (2) whether the magnitude of the emissions reduction depends on the size of the facility. To capture these effects, we added the interaction terms between ⋅ ( ≥ 2010) and

Estimation Results
the year dummies and the number of employees to the base models. Based on the Hausman's test results, the fixed effect models were accepted in all specifications.
In models 1, 3, and 5, the estimated 's are negative and statistically significant.
These results show the effectiveness of Tokyo ETS. The size of the coefficient in model 1 is 0.066, suggesting that Tokyo ETS contributed to a 6.7 percent average annual reduction in GHG emissions on average.
In addition, the interaction terms for the year dummies and Tokyo ETS are included in models 2, 4 and 6. The coefficients of these terms indicate whether the Tokyo ETS had different effects on energy usage between 2011 and 2013. We find that the coefficients of the interaction terms of the year and Tokyo ETS are negative and statistically significant.
Electronic copy available at: https://ssrn.com/abstract=3487245 We also find that the Saitama ETS dummy is negative and statistically significant in many specifications except for models 1 and 5. This result suggests that Saitama ETS was useful in reducing GHG even though it is voluntary. We did not estimate the model interacting the year dummy and Saitama ETS because of the limited number of office buildings in Saitama.
Furthermore, the results from models 2, 4 and 6 show that the coefficients of the interaction terms of the building size (employee) and Tokyo ETS are negative and statistically significant. This result suggests that the larger the building is, the greater the emission reduction is. This is an intuitive result because one would expect more room for reduction for larger facilities.
The coefficients of electricity price are negative and statistically significant. In particular, the estimates in the electricity consumption models imply that the price elasticity of demand for electricity consumption is 0.39-0.45%. Hosoe and Akiyama (2009) found that the elasticity of electricity demand ranges from 0.09 to 0.30 in the short run. Although our estimates of the elasticity seem to be relatively higher, they are comparable when we consider the confidence interval of the estimate.
Looking at the coefficients of the dummy variable for the saving request/rolling blackout, which capture the existence of a request for voluntary power savings or experience of the rolling blackout, we find no impacts on CO2 emissions, electricity consumption of energy consumption. Electronic copy available at: https://ssrn.com/abstract=3487245 Note: *** p < 0.01, ** p < 0.05, * p < 0.1

Discussion
As shown in the previous section, our preferred specification is model 1, and thus we  Figure 2.
The price in 2011 was more than $80 and fell to $50 in 2014.
Finally, we discuss the size of the emission reduction. Our estimation results show that the ETS reduced emissions in Tokyo by 6.7 percent and that the power price increase contributed another 6.4% reduction. In sum, emissions in Tokyo were reduced by 13.1 percent. This number seems rather small compared to the reduction of 25% reported by the Tokyo government. This gap can be explained by two reasons. First, the Tokyo government uses the baseline emission while we use 2009 as our reference for the

Conclusion
In this paper, we empirically investigated the impacts of Tokyo ETS using individual facility-level data for office buildings. We found that the Tokyo ETS overall has been successful in reducing CO2 emissions relative to other regions. As expected, the power price increase contributed to emissions reduction in Tokyo, but the ETS also contributed.
Thus, despite skepticism regarding the effectiveness of ETSs, it was proven that Tokyo ETS is an effective environmental policy tool.
We also recovered the implicit carbon permit price using our estimated model, which we found to be approximately $50 per CO2 ton. This price is somewhat lower than that in the Tokyo government report but still in a comparable range. One can note that the permit price in Tokyo is higher than the carbon price in Europe or North America (World Bank Group, 2019). Most of the permit prices in China's pilot scheme have been less than $15 (Duan, 2020), and the permit price in the Korean market has been stable at less than $20 (Oh, 2020). Thus, Tokyo ETS seems to have a higher carbon price.
Other aspects of Tokyo ETS, however, should be scrutinized in future work. For example, Tokyo ETS may have caused carbon leakage to other regions in Japan. Because neighborhood prefectures such as Kanagawa or Chiba have not introduced an ETS, some business may have moved or shifted economic activities to these areas from Tokyo. This is an important area of future work. Renewable Energy Credit Excess Emission Reduction Credit