DEC alternative conversion factor (LCU per US$)_

Event_Log

1. 011993Exchange-rate unification attemptAssociation

   Rafsanjani government attempts to unify Iran's multiple-tier exchange rate system; the effort partially unwinds after reserve pressure.

   Why this link: The WDI official exchange rate (PA.NUS.FCRF variant, not the chart's headline DEC/ATLS variant) jumped from 65.6 to 1,268.1 rials/US$ in 1993 -- an 1,834% devaluation -- which is literally the object the March 1993 unification policy changed. This is as close to a definitional 1:1 match as exists anywhere in this database.

   Caveat: Chart_id wdi__PA.NUS bundles three different conversion-factor variants (FCRF, ATLS, PPP) in one chart; this row specifically concerns the FCRF (official rate) series, not the DEC alternative conversion factor named in the chart's registry title.

   Lag: immediate (same year)Source: IMF Iran country page (Article IV history)
2. 022002Official/market exchange-rate unificationAssociation

   Iran unifies its official and market exchange rates at the start of the 1381 fiscal year, a rare successful unification episode.

   Why this link: The official rate jumped from 1,754.0 to 6,907.0 rials/US$ in 2002 (+293.8%), again directly the object of the cited policy: the March 2002 unification of the official and market exchange rates at the start of the 1381 fiscal year.

   Caveat: Same variant caveat as above (FCRF series specifically).

   Lag: immediate (same year)Source: IMF Iran country page (Article IV history)
3. 032012SWIFT disconnection and oil-export sanctionsAssociation

   Major Iranian banks cut off from SWIFT messaging; US NDAA sanctions target foreign purchasers of Iranian oil, triggering a sharp rial depreciation through 2012-13.

   Why this link: The official rate climbed steadily from 12,175.5 (2012) to 40,864.3 rials/US$ (2018) as the post-2012 sanctions regime pushed the government to repeatedly devalue the official rate to narrow the gap with the surging parallel market, culminating in the April 2018 unification attempt at 42,000.

   Caveat: None substantial -- this gradual multi-year devaluation is well corroborated by IMF Article IV consultation history.

   Lag: gradual over 5+ yearsSource: USIP Iran Primer — Timeline of U.S. Sanctions
4. 042018NIMA secondary forex market launchedAssociation

   The Central Bank launches the NIMA (Forex Management Integrated System) electronic platform, requiring exporters to sell foreign-currency earnings through registered exchange houses to importers of non-essential goods at a market-linked rate distinct from the official and open-market rates -- formalizing Iran's return to a multi-tier exchange-rate system just weeks after the failed April 2018 rate unification.

   Why this link: The official rate has been reported flat at exactly 42,000 rials/US$ every year from 2019 through 2023 in this WDI series -- an administrative freeze, not a market outcome. After the April 2018 unification attempt failed to hold in the open market, the government fixed a subsidized official/NIMA-adjacent rate for essential imports (see the companion 2022 '4,200 toman' elimination event) even as the free-market parallel rate (see the parallel-rate chart) kept climbing past 300,000 by 2020. The divergence between these two series is itself the direct empirical signature of Iran's return to a multi-tier exchange-rate system.

   Caveat: A rate that is fixed by administrative fiat rather than discovered by the market is not really comparable to the pre-2018 observations in the same series; direction is coded 'none' because the rate literally stops moving, which itself is the policy signal.

   Lag: immediate, then held fixed for 5 yearsSource: Atlantic Council -- Iran's Economy and the Burden of Multiple Exchange Rates