[Paper Review] An examination of the effect on the Icelandic Banking System of Ver{\dh}trygg{\dh} L\'{a}n (Indexed-Linked Loans)

Jacky Mallett|arXiv (Cornell University)|Jan 1, 2013

Banking stability, regulation, efficiency10 references3 citations

TL;DR

This paper challenges the widely held belief that Iceland's indexed-linked loans (Verðtryggð Lán) helped end hyperinflation, instead demonstrating through double-entry bookkeeping analysis that these loans mechanically fuel monetary expansion, increasing inflation by 4–12% annually. The study proposes reforming Iceland's Basel regulatory framework to stabilize money supply and break the inflationary feedback loop.

ABSTRACT

In 1979 following a decade of hyperinflation, Iceland introduced Ver{\dh}trygg{\dh} l\'an, negatively amortised, index-linked loans whose outstanding principal is increased by the rate of the consumer price inflation index(CPI). The loans were part of a general government policy which used indexation to the CPI to address the economic consequences of the hyperinflation. Although most other forms of indexation were subsequently removed, loan indexation has remained, and these loans now comprise the majority of mortgages in Iceland. Although it is still often argued that index-linked loans helped to stop the hyperinflation, these arguments are typically based on high level macro-economic interpretations of the Icelandic economy, they fail to identify specific mechanisms to support their claims. In this paper we take the opposite approach, and present a detailed analysis of the monetary mechanics used for the loans at the double entry bookkeeping level of the banking system. Based on this analysis there appears to be no evidence or mechanism that would support the claim that index-linked loans reduce or stop inflation. On the contrary: our research shows that the bookkeeping treatment of these loans within the banking system directly contributes to the banking system's monetary expansion rate, and hence index-linked loans act to increase the inflation rate to which they are linked, rather than reducing it. They consequently create a positive feedback loop within the banking system's monetary regulation operating directly on the money supply. Since the feedback into monetary expansion only occurs at annual CPI rates above approximately 2%, we suggest one solution would be to stabilise the money supply to 0% growth, and we explore some ways this could be achieved by modifying the Basel Regulatory Framework within the Icelandic Banking System.

Motivation & Objective

• . The paper investigates the actual monetary mechanics of Iceland's indexed-linked loans (Verðtryggð Lán) within the banking system.
• . It challenges the common macroeconomic claim that these loans curbed hyperinflation, arguing that no specific mechanism supports this view.
• . The objective is to analyze the loans' impact on the banking system's monetary supply using double-entry bookkeeping at the transaction level.
• . The study aims to identify how these loans create a self-reinforcing inflationary feedback loop within the monetary system.
• . It proposes policy solutions—particularly modifying the Basel regulatory framework—to stabilize Iceland's money supply and end excessive inflation.

Proposed method

• . The analysis is grounded in a complete double-entry bookkeeping model of all transactions within the Icelandic banking system.
• . The study traces the monetary mechanics of indexed-linked loans from the point of disbursement through to their impact on balance sheets and monetary aggregates.
• . It evaluates the effect of annual CPI indexation on loan principal, showing how this directly increases the money supply.
• . The paper uses conservative historical data on interest and indexation rates, prioritizing the most cautious estimates available.
• . It models the feedback loop where increased money supply leads to higher inflation, which in turn triggers further principal increases on indexed loans.
• . The proposed solution involves modifying the Basel framework to maintain constant capital and unify risk weighting, particularly removing 0% weighting for government lending.

Experimental results

Research questions

• RQ1 . Does the bookkeeping treatment of indexed-linked loans in Iceland's banking system contribute to monetary expansion and inflation?
• RQ2 . What specific mechanisms link these loans to the money supply and inflation rate, and how do they operate at the transaction level?
• RQ3 . To what extent do these loans create a self-reinforcing feedback loop that increases inflation rather than reducing it?
• RQ4 . What regulatory changes to the Basel framework could stabilize Iceland's money supply and break this feedback loop?
• RQ5 . How would a zero-growth money supply affect long-term economic indicators and systemic stability in Iceland?

Key findings

• . The indexed-linked loans in Iceland create a direct feedback loop that increases the monetary expansion rate by 4% to 12% annually.
• . The bookkeeping treatment of these loans mechanically contributes to inflation, rather than mitigating it, contradicting the common claim that they ended hyperinflation.
• . The inflationary effect is triggered only when annual CPI exceeds approximately 2%, meaning the feedback loop activates under moderate inflation.
• . The loans' negative amortization mechanism causes the outstanding principal to grow with inflation, directly expanding the money supply.
• . Without reform, borrowers will face increasing repayment difficulty due to the compounding effect of inflation-linked principal growth.
• . The study concludes that stabilizing the money supply at 0% growth—through modified Basel regulations—could end the inflationary feedback loop and restore monetary stability.