In addition, there is no previous experience of structural changes of this magnitude, which also require a very long-term perspective, and where the presence of non-linearities and irreversible tipping points are likely, conditioning the methodologies to be used. And there is limited research, and accompanying data, that explore how climate risks feed into the financial risks faced by banks. In this context, many supervisory and/or prudential authorities are opting to use stress tests and scenario analysis. The Bank of Spain is indeed preparing such stress tests for the Spanish banking sector and the results are expected to be published in Autumn. 3  A Pigouvian tax is assessed against private individuals or businesses that engage in activities with adverse side-effects for society that are not internalised by these private agents, as a result of not being an integral part of the costs and prices they face. In any case, recognition should be given to the fact that the efficacy of Pigouvian taxes may have a limit. This is because, at some point, the supply of polluting energy inputs may be so elastic that it absorbs all the taxes levied on them, without affecting demand. At that point, quantitative restrictions could become the best option. 4  As a result, we should accept that efforts to translate climate-related risks into quantifiable financial risks are in their early stages. And we will have to step up our efforts to address these problems and limitations.
Negative interest is intended to make it less attractive to hold large amounts of liquidity in Swiss francs. It is thus logical from a monetary policy perspective that banks which hold large quantities of Swiss franc liquidity relative to the size of their balance sheets should shoulder a heavier burden. As already mentioned, the introduction of negative interest rates on sight deposits at the SNB has also caused longer-term interest rates to fall. And yet, we have been living through a period of exceptionally low interest rates for around six years already, with even long-term investments bearing virtually no interest. The Swiss are a nation of savers and many people are concerned about low interest rates. I understand this, however we should not forget that what really counts for savers is not the nominal but the real (i.e. inflation-adjusted) interest rate. For some time now, inflation has been very low and now it is even negative. If inflation is negative, the real interest rate is higher than the nominal interest rate. As chart 5 shows, there have often been periods in the past when real interest rates were even lower than they are today. During this challenging phase for the Swiss economy, it is important that the negative interest rate be allowed to take effect and help to bring about a weakening of the Swiss franc. Efforts to circumvent negative interest rates by obtaining exemptions or shifting to cash are not in the interests of Switzerland as a whole in the current climate.