| Literature DB >> 33921236 |
Haoxuan Hu1, Yuchen Zhang2, Xi Rao3, Yinghua Jin4.
Abstract
China's high economic growth has been accompanied by deteriorating air quality in recent decades. This paper aims to explore the relation between technology innovation (defined as the invention patent counts of each region) of new energy vehicles (NEVs) in China and air quality. A panel fixed effect model is used to analyze this relation and the mediating effect methods are used to examine the role of the output of NEVs (defined as the annual production quantity of NEVs in each region (unit: thousand)). The results of our study show: (1) the impact of the technology innovation of NEVs on air quality is positive and statistically significant; (2) the mediating role of the output of NEVs is confirmed in the relation between NEVs innovation and air quality improvement; (3) the technology innovation of NEVs has a more notable impact on the air quality in the regions with higher vehicle and vessel tax (VVT). The present study implicates for the first time that the technology innovation of NEVs can enhance air quality with the mediating role of the output of NEVs and the moderating role of VVT.Entities:
Keywords: air pollution; new energy vehicles (NEVs); technology innovation; vehicle and vessel tax (VVT)
Year: 2021 PMID: 33921236 PMCID: PMC8069163 DOI: 10.3390/ijerph18084025
Source DB: PubMed Journal: Int J Environ Res Public Health ISSN: 1660-4601 Impact factor: 3.390
Descriptive statistics.
| Variables | Definition | Mean | SD | Min | Median | Max | |
|---|---|---|---|---|---|---|---|
| Dependent Variable | AQI | Number of days of air quality excellent status (day) | 263.200 | 60.700 | 93 | 260 | 362 |
| Independent Variable | Patent | Number of NEVs invention patent (piece) | 26.330 | 70.660 | 0 | 3 | 523 |
| Control Variable | POP | Population (ten thousand) | 4954 | 7540 | 317.600 | 3811.700 | 100,047 |
| 2nd Industry | The proportion of GDP in the secondary industry (%) | 41.350 | 7.844 | 16.200 | 42.584 | 54.140 | |
| VVT Sum | Sum of VVT (ten thousand yuan) | 232,409 | 176,065 | 7647 | 181,762 | 843,520 | |
| Forest | Forest coverage rate (%) | 33.000 | 18.090 | 4.240 | 35.840 | 66.800 | |
| Mediator Variable | Output | Output of NEVs (ten thousand) | 2.389 | 3.155 | 0 | 1.100 | 15.440 |
| Moderator Variable | VVT | 1–1.6 L emissions VVT in 31 provinces (yuan) | 335.500 | 43.960 | 300 | 350 | 420 |
NEV: new energy vehicle; VVT: vehicle and vessel tax; AQI: air quality; POP: population.
Pearson’s correlations and Spearman’s correlations of variables.
| AQI | Patent | POP | 2nd Industry | Sum | Forest | Output | VVT | |
|---|---|---|---|---|---|---|---|---|
| AQI | 0.317 *** | 0.067 ** | 0.079 ** | 0.070 *** | 0.147 ** | 0.191 ** | 0.076 *** | |
| Patent | 0.377 *** | 0.017 *** | −0.199 ** | −0.313 ** | −0.297 *** | 0.208 * | −0.203 *** | |
| POP | 0.045 * | 0.022 ** | 0.217 ** | −0.305 * | 0.312 ** | 0.171 *** | 0.509 ** | |
| 2nd Industry | 0.063 ** | −0.225 * | 0.123 | 0.204 ** | 0.355 *** | 0.041 ** | 0.336 ** | |
| VVT Sum | 0.057 * | −0.253 ** | −0.170 ** | 0.140 ** | 0.102 * | −0.025 * | 0.082 * | |
| Forest | 0.133 *** | −0.376 * | 0.126 *** | 0.394 * | 0.078 * | 0.216 *** | 0.578 ** | |
| Output | 0.212 ** | 0.394 * | 0.166 *** | 0.028 ** | −0.038 | 0.253 *** | 0.149 * | |
| VVT | 0.088 ** | −0.144 *** | 0.388 * | 0.357 * | 0.095 ** | 0.320 * | 0.123 |
Note: Robust t-statistics are reported in parentheses. *, **, and *** indicate statistical significance at the 10%, 5%, and 1% levels, respectively.
Breitung panel unit root tests.
| Variables | Constant |
|---|---|
| AQI | −0.909 *** |
| 0 | |
| Patent | −1.023 ** |
| −0.005 | |
| Output | −1.003 ** |
| −0.002 | |
| VVT | −2.077 ** |
| −0.006 | |
| 2nd Industry | 1.579 * |
| −0.002 | |
| POP | 1.958 *** |
| 0 | |
| Forest | 2.905 *** |
| 0 |
Note: ***, ** and * indicate stationarity at 1%, 5%, and 10% significance levels, respectively. p-value are reported in parentheses.
Granger causality Wald tests.
| Equation | Excluded | Chi-Square | Prob > Chi-Square |
|---|---|---|---|
| AQI | Patent | 7.812 | 0.005 |
| Patent | AQI | 0.066 | 0.798 |
Innovation and AQI—baseline analysis.
| Dependent Variable | AQI | (1) | (2) |
|---|---|---|---|
| Independent Variable | Patent | 1.012 *** | 1.034 *** |
| (2.741) | (2.973) | ||
| Control Variable | POP | 0.010 * | |
| (1.900) | |||
| Forest | −0.017 ** | ||
| (−2.305) | |||
| 2nd Industry | −0.011 ** | ||
| (−2.597) | |||
| VVT Sum | −0.103 * | ||
| (−1.896) | |||
| Constant | −71.884 *** | −59.552 * | |
| (−5.366) | (−1.694) | ||
| Year FE | YES | YES | |
| Province FE | YES | YES | |
| Observations | 186 | 186 | |
| Adj.R2 | 0.360 | 0.336 | |
Note: Robust t-statistics are reported in parentheses. *, **, and *** indicate statistical significance at the 10%, 5%, and 1% levels, respectively; FE: fixed effect.
Panel fixed effect regression results of Model 2 and Model 3.
| Dependent Variable | Model 2 | Model 3 | ||
|---|---|---|---|---|
| Output | AQI | |||
| Independent Variable | Patent | 0.673 *** | Patent | 0.019 *** |
| Output | 0.023 *** | |||
| Control Variable | POP | 0.017 *** | POP | 0.031 ** |
| (2.918) | (2.336) | |||
| Forest | −0.002 | Forest | 0.007 *** | |
| (−0.195) | (8.824) | |||
| 2nd Industry | 0.043 * | 2nd Industry | −0.006 *** | |
| (1.819) | (−2.993) | |||
| VVT Sum | 0.983 *** | VVT Sum | −0.157 *** | |
| (4.045) | (−8.347) | |||
| Constant | −12.636 *** | Constant | 7.384 *** | |
| (−4.487) | (33.459) | |||
| Year FE | YES | Year FE | YES | |
| Province FE | YES | Province FE | YES | |
| Observations | 186 | Observations | 186 | |
| Adj.R2 | 0.319 | Adj.R2 | 0.385 | |
Note: Robust t-statistics are reported in parentheses. *, **, and *** indicate statistical significance at the 10%, 5%, and 1% levels, respectively.
VVT moderator effect test results in two groups.
| Dependent Variable | AQI | ||
|---|---|---|---|
| Low Tax Group | High Tax Group | ||
| Independent Variable | Patent | 0.017 | 8.622 *** |
| (1.633) | (3.027) | ||
| Control Variable | POP | 0.001 * | −15.451 |
| (1.882) | (−1.265) | ||
| Forest | 0.003 | 1.877 *** | |
| (1.913) * | (7.619) | ||
| 2nd Industry | −0.017 *** | −57.865 *** | |
| (−3.235) | (−3.297) | ||
| VVT Sum | −0.362 | −29.897 *** | |
| (−1.556) | (−2.758) | ||
| Constant | −75.244 | 783.878 *** | |
| (−1.264) | (5.070) | ||
| Year FE | YES | YES | |
| Province FE | YES | YES | |
| Observations | 102 | 84 | |
| Adj.R2 | 0.394 | 0.441 | |
| Difference | 0.908 | ||
| Chi-square | 5.12 *** | ||
Note: Robust t-statistics are reported in parentheses. *, and *** indicate statistical significance at the 10%, and 1% levels, respectively.
Innovation and AQI—robustness test (only air quality directly related invention patents included).
| Dependent Variable | AQI | (1) | (2) |
|---|---|---|---|
| Independent Variable | Patent | 1.725 *** | 1.116 *** |
| (2.945) | (2.790) | ||
| Control Variable | POP | 0.009 * | |
| (1.913) | |||
| Forest | −0.020 ** | ||
| (−2.311) | |||
| 2nd Industry | −0.016 ** | ||
| (−2.479) | |||
| VVT Sum | −0.121 * | ||
| (−1.877) | |||
| Constant | −60.894 *** | −52.769 * | |
| (−4.277) | (−1.701) | ||
| Year FE | YES | YES | |
| Province FE | YES | YES | |
| Observations | 186 | 186 | |
| Adj.R2 | 0.323 | 0.307 | |
Note: Robust t-statistics are reported in parentheses. *, **, and *** indicate statistical significance at the 10%, 5%, and 1% levels, respectively.
The indicators of VVT in 31 provincial administra-tive regions (yuan/year) and the preferential policies about VVT in mainland China.
| Type | Province | <1 L | 1–1.6 L | 1.6–2 L | 2–2.5 L | 2.5–3 L | 3–4 L | >4 L |
|---|---|---|---|---|---|---|---|---|
| Low Tax Regions | Chongqing | 120 | 300 | 360 | 660 | 1200 | 2400 | 3600 |
| Ningxia | 120 | 300 | 360 | 660 | 1800 | 3000 | 4500 | |
| Qinghai | 60 | 300 | 360 | 660 | 1500 | 2700 | 4200 | |
| Sichuan | 180 | 300 | 360 | 720 | 1800 | 3000 | 4500 | |
| Hainan | 60 | 300 | 360 | 720 | 1500 | 2700 | 4200 | |
| Anhui | 180 | 300 | 360 | 660 | 1200 | 2700 | 3900 | |
| Fujian | 180 | 300 | 360 | 720 | 1500 | 2640 | 3900 | |
| Tibet | 60 | 300 | 360 | 660 | 1200 | 2400 | 3600 | |
| Zhejiang | 180 | 300 | 360 | 660 | 1500 | 3000 | 4500 | |
| Guizhou | 180 | 300 | 360 | 660 | 1200 | 2400 | 3600 | |
| Hunan | 120 | 300 | 360 | 720 | 1920 | 3120 | 4800 | |
| Jiangsu | 120 | 300 | 360 | 660 | 1200 | 2400 | 3600 | |
| Jiangxi | 180 | 300 | 360 | 660 | 1200 | 2400 | 3600 | |
| Yunnan | 60 | 300 | 390 | 780 | 1800 | 3000 | 4500 | |
| Henan | 180 | 300 | 420 | 720 | 1500 | 3000 | 4500 | |
| Shanxi | 180 | 300 | 480 | 900 | 1800 | 3000 | 4500 | |
| Hebei | 120 | 300 | 480 | 840 | 1800 | 3000 | 4500 | |
| High Tax Regions | Beijing | 250 | 350 | 400 | 750 | 1600 | 2900 | 4400 |
| Inner Mongolia | 300 | 360 | 420 | 900 | 1800 | 3000 | 4500 | |
| Guangdong | 180 | 360 | 420 | 720 | 1800 | 3000 | 4500 | |
| Shandong | 240 | 360 | 420 | 900 | 1800 | 3000 | 4500 | |
| Xinjiang | 180 | 360 | 420 | 720 | 1800 | 3000 | 4500 | |
| Hubei | 240 | 360 | 420 | 720 | 1800 | 3000 | 4500 | |
| Guangxi | 60 | 360 | 420 | 780 | 1800 | 3000 | 4500 | |
| Shanghai | 180 | 360 | 450 | 720 | 1500 | 3000 | 4500 | |
| Tianjin | 270 | 390 | 450 | 900 | 1800 | 3000 | 4500 | |
| Liaoning | 300 | 420 | 480 | 900 | 1800 | 3000 | 4500 | |
| Gansu | 240 | 420 | 480 | 720 | 1800 | 3000 | 4500 | |
| Shaanxi | 180 | 360 | 480 | 720 | 1800 | 3000 | 4500 | |
| Jilin | 240 | 420 | 480 | 900 | 1800 | 3000 | 4500 | |
| Heilongjiang | 240 | 420 | 480 | 900 | 1800 | 3000 | 4500 |
Note: data were obtained from the provinces’ vehicle and vessel tax charge documents.