Speculation and retail price transmission in the frozen concentrated orange juice market: a causal machine learning analysis
摘要
While the futures–spot price relationship is well established in commodity markets, the transmission of price signals to the retail level remains an "incomplete bridge,” particularly under varying speculative regimes. Traditional empirical approaches often fail to capture the nonlinear and heterogeneous dynamics of this process, typically providing a single Average Treatment Effect (ATE) that masks the distortions caused by market frictions. This study addresses this gap by developing a novel causal machine learning (CML) framework. Leveraging double machine learning (DML), we isolate the causal link between futures and retail prices by "partialing out” high-dimensional confounding variables, effectively distinguishing the informational signal from the market "noise” identified in recent literature. We illustrate this framework using the US frozen concentrated orange juice (FCOJ) market as a functional laboratory for concentrated and volatile ”soft” commodities. Our results reveal a non-monotonic relationship: while moderate speculation enhances price discovery (CATE