The granular origins of exchange-rate fluctuations

Simon Lloyd, Daniel Ostry and Balduin Bippus

How much capital flows move exchange rates is a central question in international macroeconomics. A major challenge to addressing it has been the difficulty identifying exogenous cross-border flows, since flows and exchange rates can evolve simultaneously with factors like risk sentiment. In this post, we summarise a staff working paper that resolves this impasse using bank-level data capturing the external positions of UK-based global intermediaries to construct novel ‘Granular Instrumental Variables‘ (GIVs). Using these GIVs, we find that banks’ United States dollar (USD) demand is inelastic – a 1% increase in net-dollar assets appreciates the dollar by 2% against sterling – state dependent – effects double when banks’ capital ratios are one standard deviation below average – and that banks are a ‘marginal investor’ in the dollar-sterling market.

Continue reading →

Bias, fairness, and other ethical dimensions in artificial intelligence

Kathleen Blake

Artificial intelligence (AI) is an increasingly important feature of the financial system with firms expecting the use of AI and machine learning to increase by 3.5 times over the next three years. The impact of bias, fairness, and other ethical considerations are principally associated with conduct and consumer protection. But as set out in DP5/22, AI may create or amplify financial stability and monetary stability risks. I argue that biased data or unethical algorithms could exacerbate financial stability risks, as well as conduct risks.

Continue reading →

Unifying monetary and macroprudential policy

Julia Giese, Michael McLeay, David Aikman and Sujit Kapadia

Central banks have been using a range of monetary policy and macroprudential tools to maintain monetary and financial stability. But when should monetary versus macroprudential tools be used and how should they be combined? Our recent paper develops a macroeconomic model to answer these questions. We find that two instruments are better than one. Used alone, interest rates can control inflation, but are ineffective for financial stability. Policymakers can do better by also deploying the countercyclical capital buffer, a tool that varies the amount of additional capital banks must set aside. The appropriate combination of tools can vary: both should tighten to counter a joint expansion of credit and activity, but move in opposite directions during an exuberance-driven credit boom.

Continue reading →