By potential output and potential growth we mean instead the output and growth that is possible without serious imbalances arising in the economy; the level of output at which supply and demand correspond and actual and expected inflation are in line with the central bank’s inflation target (assuming that there is one). The potential output level is not constant over time; it usually shows a growth trend, which is illustrated in Figure 1. This is mainly because technological developments mean that higher output can be achieved with the same amount of factors of production. Another reason could be long-term changes in the factors of production. The change in potential output from year to year is equal to the potential growth of the economy, which thus is the growth rate that is sustainable in the long term. Figure 1 shows the potential output level according to a simple statistical method where the trend, and thereby also the potential growth rate, is allowed to vary over time. The difference between actual and potential output is known as the output gap, and this reflects the cyclical variations in the economy. A negative output gap, that is to say, when actual output is lower than potential output, is usually connected with a recession. The demand pressure for goods, services and the factors of production is then small and there are ample unutilised resources in the economy. Price and wage increases are small and inflation is usually below the central bank’s target level.
Consequently, Switzerland – unlike other countries – was able to avoid introducing state-guaranteed bonds. With the drastic reduction in key rates and the subsequent decline in mortgage rates, the burden on households and companies was eased. In this way, the severity of the recession was somewhat alleviated and the risks of deflation reduced. However, the interest rate is now at a historic low and this means medium-term risks for the Swiss real estate market and financial stability. Experience shows that periods of low interest rates provide scope for excesses on the mortgage and real estate market. Consequently, in the current environment in particular, attention should be given to ensuring that past mistakes are not repeated. Caution must remain the watchword when granting loans. BIS Review 140/2009  1