I wish more people had dared to work on disruptions of energy supply (or global value chains) a few years ago. Likewise, the latest report of the Working Group III of the IPCC (dedicated to climate mitigation) contains a chapter (#5) that places great emphasis on the need for sufficiency and behavioral changes, and it discusses the literature exploring how we could thrive as societies and individuals without depending so much on GDP growth. Professor Dasgupta also invites us not only to acknowledge that GDP growth will be limited at some point even if you are a techno-optimist, but also to think about new approaches to economic value and social well-being that do not rely on GDP. All this begs us, and especially the young scholars present today, to ask what will be essential in 5 to 10 years from now. In addition to this need to promote new approaches, it is urgent to act. 9  Page 10 sur 12 We cannot afford to lose time or to wait until we have elaborated “perfect” tools. We need to seek how transformative changes can be implemented as soon as possible and if needed, develop and revise our scenarios, metrics, approaches. The responsibility to revert nature loss falls first and foremost with governments, and no central bank – above all in a democracy - can replace them.
It may partly reflect very low levels of current policy rates and any spillovers from that.3 It may also reflect the term premia for inflation that are currently very compressed in some countries, for example, the US and in the Euro area. And it may also be a symptom of a more entrenched pessimism – an over-pessimism in my view – about long-term economic prospects, possibly due to fears of the de-integration of the global economy or concerns about future effectiveness of monetary policy. But, more fundamentally, the very low level of market interest rates reflects an underlying structural trend – the fall in long-run real interest rates since the early 1980s4 – that has been the subject of a great deal of research. The literature has identified a large number of candidate explanations – both real and financial – for a structural decline in the long-run real interest rate. These include: demographic trends and, in particular, increased longevity; lower trend productivity growth; the liberalization of financial intermediation and an increase in the risk borne by individuals and households.5  The long-run equilibrium real interest rates determined by these factors are, of course, unobservable. There is a range of estimates for how far they have fallen.