Fiscal discipline shapes how central bank independence affects inflation volatility

What the study found: Central bank independence (CBI), meaning the extent to which a central bank can act without political control, did not by itself have a significant effect on inflation volatility in Tunisia. The study found that high legal independence was slightly associated with more inflation fluctuation, while stronger independence under fiscal pressure was linked to lower volatility.

Why the authors say this matters: The authors conclude that legal independence alone is not enough and that a coherent macroeconomic framework, including fiscal discipline and coordination between monetary and fiscal authorities, is needed. The findings indicate that transparency and credible fiscal signals also shape how inflation stability is affected.

What the researchers tested: The study examined determinants of inflation volatility in Tunisia using a theoretical game-theory framework and two empirical approaches: a binary threshold nonlinear autoregressive distributed lag (NARDL) model, which is used to study long-run relationships, and a Markov-switching GARCH (MS-GARCH) model, which is used to model changing volatility over time.

What worked and what didn't: As a continuous measure, CBI had no significant impact on volatility. In a binary regime, high de jure independence was associated with a slight increase in inflation fluctuations, but under fiscal pressure greater CBI substantially reduced inflation volatility. Economic transparency generally increased short-term volatility but helped stabilize inflation when backed by credible fiscal signals; broad money volatility was strongly destabilizing, while industrial production and the real exchange rate were largely insignificant.

What to keep in mind: The study is about Tunisia, so its findings are specific to a small open economy. The abstract does not describe detailed limitations beyond the scope of the country and the variables studied.

Key points

• CBI had no significant effect on inflation volatility when measured continuously.
• High legal independence was slightly associated with higher inflation fluctuations in a binary regime.
• Under fiscal pressure, greater CBI substantially reduced inflation volatility.
• Economic transparency generally increased short-term volatility but stabilized inflation when fiscal signals were credible.
• Broad money volatility was strongly destabilizing; industrial production and the real exchange rate were largely insignificant.