When Chinese mania meets global frenzy: Commodity price bubbles
研究全球大宗商品价格泡沫，发现正向泡沫更多由基本面冲击驱动，负向泡沫受悲观市场看法影响；中国泡沫受交易者行为和政策不确定性影响，全球泡沫则受库存、增长和通胀等理性因素主导。
This paper examines price bubbles in global commodity markets. We find that positive bubbles are more driven by fundamental shocks, while negative bubbles are more influenced by pessimistic market views on prices and the economy. Furthermore, bubble determinants vary across geographic regions. Trader behavior and policy uncertainty play prominent roles in influencing price bubbles in China, while global bubbles are predominantly shaped by rational responses to inventory, growth, and inflation. Finally, only positive bubbles exhibit contagion across regions. Overall, our findings suggest that asset price bubbles arise from traders' behavioral responses to a combination of fundamental, macroeconomic, and idiosyncratic shocks.