Hoard Behavior and Commodity Bubbles

Working Paper: NBER ID: w20974

Authors: Harrison Hong; Ureo de Paula; Vishal Singh

Abstract: Hoarding by large speculators is often blamed for contributing to commodity market panics and bubbles. Using supermarket scanner data on US household purchases during the 2008 Rice Bubble, we show that hoarding is in fact more systemic, affecting even households who have no resale motive. Export bans led to a spike in prices worldwide in the first half of 2008, which spilled over into US markets. Anticipating shortages, US households with previous purchases of rice, especially those of Asian ethnicity, nearly doubled their buying around the peak of the bubble. We document transmission mechanisms through over-extrapolation from high prices and contagion, as many households bought rice for the first and last time during the bubble.

Keywords: hoarding; commodity bubbles; rice market; consumer behavior

JEL Codes: G0


Causal Claims Network Graph

Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.


Causal Claims

CauseEffect
Price increases (E30)Hoarding behavior (D10)
Higher prices (D49)Increased expectations of future price rises (D84)
Increased expectations of future price rises (D84)Hoarding behavior (D10)
Hoarding behavior (D10)Increased rice purchases (Q17)
Hoarding behavior (D10)Strategic consumption adjustments (E21)
Price spikes (D49)Household purchasing behavior (D10)

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