Adjustable Peg

An adjustable peg is an exchange-rate regime that keeps a currency near a declared parity most of the time but allows occasional realignment when the old peg becomes too costly to defend. It is often described as fixed but adjustable.

$$$$

How The Regime Works

The central bank or monetary authority tries to keep the exchange rate close to a target by:

buying or selling foreign-exchange reserves,
adjusting interest rates,
sometimes using capital-flow controls or prudential limits.

If external deficits, reserve losses, or inflation differentials make the old parity unsustainable, the authority can devalue or revalue the peg instead of defending it forever.

Exchange rate moving inside a narrow band around an old parity and then shifting to a new band after a realignment. — An adjustable peg holds the exchange rate near a declared parity until pressure becomes strong enough to trigger a realignment.

Why It Is Hard To Maintain

The regime sits inside the classic policy trilemma. With open capital flows, a country cannot simultaneously maintain:

a fixed exchange rate,
independent monetary policy,
and fully free capital mobility.

That means domestic policy is constrained whenever defending the peg conflicts with internal goals such as growth or employment.

Expectations And Speculative Pressure

Once markets expect devaluation, defending the peg becomes even harder. A useful intuition comes from uncovered interest parity:

\[ i \approx i^* + \mathbb{E}[\Delta s] + \rho \]

If expected depreciation rises, the domestic interest rate may need to rise as well to discourage capital outflow. That can hurt domestic demand and the banking system, making the defence of the peg increasingly expensive.

Why Countries Use Adjustable Pegs Anyway

Despite the risks, governments may prefer adjustable pegs because they offer more exchange-rate stability than a pure float while retaining more flexibility than a perfectly rigid fixed rate. The trade-off is that the occasional realignment itself can become the object of speculation.

Knowledge Check

### What makes an adjustable peg different from a permanently fixed exchange rate? - [x] The authority may occasionally change the parity when the old one becomes unsustainable - [ ] The exchange rate never moves at all - [ ] The regime uses no reserves - [ ] It eliminates speculative pressure > **Explanation:** The defining feature is not day-to-day flexibility but the option to reset the peg when pressure becomes too great. ### Why can speculation make an adjustable peg harder to defend? - [ ] Because it automatically raises exports - [x] Because expected devaluation encourages capital outflow and reserve loss - [ ] Because it makes inflation impossible - [ ] Because the peg becomes a floating rate immediately > **Explanation:** If investors expect the peg to break, they try to sell early, which increases pressure on reserves and interest rates. ### What is the main policy trade-off behind an adjustable peg? - [ ] It guarantees independent monetary policy and free capital flows at the same time - [ ] It removes the need for balance-of-payments adjustment - [x] It offers more exchange-rate stability than a float but less rigidity than a hard peg - [ ] It abolishes exchange-rate risk > **Explanation:** The regime is a compromise: some stability, some flexibility, and persistent vulnerability to credibility problems.