G-SIB capital rules show cross-jurisdictional variance
A new Bank for International Settlements (BIS) study documents the varied components of global systemically important banks' (G-SIBs) capital requirement stacks. The research highlights how national flexibility in applying Basel III leads to cross-jurisdictional differences.
Basel III flexibility creates varied capital stacks
Following the Great Financial Crisis, Basel III introduced comprehensive capital reforms to bolster global banking system resilience, increasing capital quality and minimum requirements.
While Basel III sets a common baseline for internationally active banks, national authorities retain flexibility to exceed these minimum standards, tailoring requirements to reflect structural differences and supervisory considerations.
This flexibility, particularly through Pillar 2, allows supervisors to impose higher requirements where Pillar 1 falls short.
However, these heterogeneous applications of Basel III have fueled perceptions of an uneven playing field and challenge cross-jurisdictional comparisons of capital standards.
This paper documents the various components of G-SIBs' overall capital requirement stacks and discusses potential drivers of these differences, relying on a hand-collected, harmonised dataset covering 29 G-SIBs from seven jurisdictions for the period 2014–25.
Divergent buffers and risk weight approaches
The data reveal that the composition of capital stacks is heterogeneous across jurisdictions, with the number of different elements ranging from four to eight.
While minimum capital requirements are globally consistent, some jurisdictions demand a greater extent of higher-quality capital than Basel III prescribes.
Individual components, excluding minima, contribute significantly to the overall ratio, from 0.1 to 3 percentage points on average across banks in different jurisdictions.
Differences in required capital ratios partly stem from varying levels of systemic importance, with G-SIB buffers ranging from 1% to 2.5% of risk-weighted assets (RWA), and some jurisdictions imposing even higher surcharges up to 4.5%.
Comparisons are further complicated by heterogeneous approaches to computing risk weights, with suggestive evidence of differing degrees of conservatism in risk measurement.
Convergence challenged by national discretion
This study underscores the inherent tension in global banking regulation: while Basel III aims for a common baseline, national authorities' flexibility creates significant divergence in actual capital requirements.
This heterogeneity risks undermining market discipline and fostering perceptions of an uneven playing field, despite efforts to enhance transparency.
Ultimately, true comparability remains elusive as long as national discretion allows for such varied interpretations and add-ons, complicating both supervision and market assessment.