Huigang Chen

Capital Controls or Exchange Rate Policy? A Pecuniary Externality Perspective

In the aftermath of the global financial crisis, a new policy paradigm has emerged in which old-fashioned policies such as capital controls and other government distortions have become part of the standard policy toolkit (the so-called macro-prudential policies). On the wave of this seemingly unanimous policy consensus, a new strand of theoretical literature contends that capital controls are welfare enhancing and can be justified rigorously because of second-best considerations. Within the same theoretical framework adopted in this fast-growing literature, we show that a credible commitment to support the exchange rate in crisis times always welfare-dominates prudential capital controls as it can achieve the first best unconstrained allocation. In this benchmark economy, prudential capital controls are optimal only when the set of policy tools is restricted so that they are the only policy instrument available.

Optimal Policy for Macro-Financial Stability

In this paper we study whether policy makers should wait to intervene until a financial crisis strikes or rather act in a preemptive manner. We study this question in a relatively simple dynamic stochastic general equilibrium model in which crises are endogenous events induced by the presence of an occasionally binding borrowing constraint as in Mendoza (2010). First, we show that the same set of taxes that replicates the constrained social planner allocation could be used optimally by a Ramsey planner to achieve the first best unconstrained equilibrium: in both cases without any precautionary intervention. Second, we show that the extent to which policymakers should intervene in a preemptive manner depends critically on the set of policy tools available and what these instruments can achieve when a crisis strikes. For example, in the context of our model, we find that, if the policy tools is constrained so that the first best cannot be achieved and the policy maker has access to only one tax instrument, it is always desirable to intervene before the crisis regardless of the instrument used. If however the policy maker has access to two instruments, it is optimal to act only during crisis times. Third and finally, we propose a computational algorithm to solve Markov-Perfect optimal policy for problems in which the policy function is not differentiable.

Optimal capital controls and real exchange rate policies: A pecuniary externality perspective

A new literature studies the use of capital controls to prevent financial crises. Within this new framework, we show that when exchange rate policy is costless, there is no need for capital controls. However, if exchange rate policy entails efficiency costs, capital controls become part of the optimal policy mix. When exchange rate policy is costly, the optimal mix combines prudential capital controls in tranquil times with policies that limit exchange rate depreciation in crisis times. The optimal mix yields more borrowing, fewer and less severe financial crises, and much higher welfare than with capital controls alone.