The Limit of Evil: Effects of Inflation and Public Debt on Capital Market Development

It is almost self-evident that capital markets can thrive only in a benign macroeconomic environment. What is often overlooked is that malign macro factors such as inflation and government debt, provided that they are kept under control, can have their bright sides. Previous studies typically presume that the impact of inflation or government debt on capital market development is monotonic, thus precluding the possibility that these factors could be beneficial within a certain limit or threshold. In this study, we take into account this possibility. Our study finds an inverted U-shaped relationship between inflation and the size of the stock market. Hence, inflation within a certain limit may act as a lubricant to the market and help lower the cost of capital in real terms. However, when inflation is too high, long-term investment decisions would be difficult, which is detrimental to stock market growth. An inverted U-shaped relationship is also found between the size of the government bond market and that of the corporate bond market. This suggests that public debt under a certain threshold can benefit corporate bond market development, supporting the notion that the sovereign yield curve plays an important role in pricing private sector debt securities. However, excessive public debt would stifle it.