Why Persian Gulf state de-dollarisation is self-completing once it starts. The supermodular network externality model that explains when Saudi Arabia, UAE, Iraq, Kuwait, and Qatar cross the tipping threshold — and why the cascade, once entered, cannot be reversed.
Each additional switcher adds exactly ν to the yuan side's attractiveness. This is a network externality: the value of the yuan payment rail increases with usage. CIPS liquidity, tighter FX spreads, deeper market-making — all improve as volume grows.
When Saudi Arabia begins yuan pricing, the U.S. guarantee to UAE becomes less credible: if Washington cannot keep Riyadh in the dollar system, can it keep Abu Dhabi? Each defection signals that the guarantee is revocable, reducing its strategic value for remaining states.
Below k*, remaining in the dollar system is rational. At or above k*, switching to yuan is rational. The tipping point k* is not symmetric: it is easier to pass it than to reverse it, because the guarantee decay is permanent while the network gain is cumulative.
A Persian Gulf state that has switched to yuan pricing has demonstrated that the U.S. guarantee is insufficient. Reversing that signal requires U.S. actions so costly (military deployment, formal treaty upgrade) that they are rarely achievable. The cascade is a one-way valve.
Each Persian Gulf state faces the cascade inequality with different parameter values. The knife-edge varies by state based on U.S. military dependence, Chinese trade exposure, bypass pipeline access, and existing yuan infrastructure participation.
Number of switchers required to reach tipping point (k*) across network effect ν and guarantee erosion δ. Lower k* = faster cascade. Current estimated zone highlighted.
| ν \ δ | δ=0.05 | δ=0.10 | δ=0.15 | δ=0.20 | δ=0.25 |
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Adjust parameters and watch the cascade trajectory. The chart shows the yuan side (G_s + kν) vs the guarantee side (P_s(0)(1−δ)^k) as k rises from 0 to 10.