ABSTRACT
We use the time-varying parameter structural vector autoregression stochastic volatility (TVP-SVAR-SV) and causality-in-quantiles methods to explore the linkage between market liquidity and efficiency in the European Union Emissions Trading Scheme (EU ETS) during Phase III. Our results show that two-way causality existed under normal and lower market conditions. Additionally, the linkage between liquidity and efficiency exhibits time-varying characteristics. Except in cases of extremely high market liquidity, the pass-through effect of liquidity on efficiency is mostly positive in the long run. The linkage is stronger in the medium and long term, but the response of liquidity to efficiency shocks is more complicated. Market efficiency has an overall inhibitory effect on liquidity in the short term and a promoting effect in the medium and long term. Furthermore, we investigate the impulse response during the COVID-19 period and the war between Russia and Ukraine and find that improvements in efficiency will permanently damage liquidity. Overall, the abilities of market makers and arbitrage traders, impacted by multiple factors, play an important role in the process by which liquidity affects market efficiency. By revealing and explaining the dynamic relationship between liquidity and efficiency, this research provides valuable information for policymakers and various market participants.
ABSTRACT
Since the outbreak of the COVID-19 pandemic, a growing body of literature has focused on the impact of the uncertainty of the world pandemic (WPU) on commodity prices. Using the quarterly data from the first quarter of 2008 to the second quarter of 2020, we run the TVP-SVAR-SV model to study the time-varying impact of WPU on China's commodity prices. Specifically, we select minerals, non-ferrous metals, energy and steel commodities for a categorical comparison and measure the impact of WPU accordingly. The findings are as follows. First, WPU has a significant time-varying impact on China's commodity prices, and the short-term effect is greater than the long-term effect. Second, compared with the global financial crisis in the fourth quarter of 2008 and China's stock market crash in the second quarter of 2015, WPU had a greatest impact on Chinese commodity prices during the COVID-19 pandemic event in the fourth quarter of 2019. Third, significant differences exist in the impact of WPU on the four major commodity prices. Among them, WPU has the largest time-varying impact on the price of minerals but the smallest time-varying impact on that of steel.