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The Taylor Rule’s Zero Lower Bound problem can be solved by pegging interest rates on longer-maturity loans than the 6 weeks implicit in the Fed’s current operating procedures. However, the Fed’s policy since 2008 of reducing the opportunity cost of excess reserves to zero (or even negative) has neutralized the stimulative effect of the Fed’s low interest rate policy. Eliminating interest on excess reserves would restore the effectiveness of monetary policy, but would require promptly unwinding the Fed’s “Quantatitve Easing” acquisitions.

It is argued that the Fed’s reaction function should contain no pure inertial terms, and that the “output gap” as originally conceived by Taylor is a statistical illusion. Although the unemployment gap is statistically meaningful, it is not clear that it should be directly included in the Taylor Rule unless it serves as a proxy for the equilibrium real interest rate.

Mehra and Prescott (1985) point out that it is difficult to reconcile certain empirical facts about equity and debt returns and the process of consumption growth with reasonable assumptions about the relative rate of risk aversion and the pure rate of time preference, in a conventional infinite-horizon model with an additively separable, constant relative rate of risk aversion (CRRA) utility function. The present note adds the further puzzle that if the mean rate of growth of consumption is not known with perfect certainty in such a model, both stocks and real perpetuities have an infinite price in terms of consumption goods. When maturity-specific claims on real output are introduced, the equity premium is seen to increase without bound at the most distant horizons. These in turn dominate asset pricing, so that the equity premium on claims on all future output is indeed infinite.

This study uses parametric hazard models to investigate duration dependence in US stock market cycles over the January 1929 through December 1992 period. Market cycles are determined using the Beveridge‐Nelson (1981) approach to the decomposition of economic time series. The results show that both real and nominal cycles exhibit positive duration dependence. The implication of this finding is that actual prices revert to their permanent or trend level in a non‐random manner as the cyclical component dissipates over time. This process is consistent with mean reversion in price and suggests that predictable periodicity in market cycles may exist. Only limited evidence is obtained that discrete shifts or trends in mean cycle duration exist. The length of market cycles appears not to have changed over the 1929–92 period.

The purpose of this paper is to review cases of artificial reefs built through additive manufacturing (AM) technologies and analyse their ecological goals, fabrication process, materials, structural design features and implementation location to determine predominant parameters, environmental impacts, advantages, and limitations.

The review analysed 16 cases of artificial reefs from both temperate and tropical regions. These were categorised based on the AM process used, the mortar material used (crucial for biological applications), the structural design features and the location of implementation. These parameters are assessed to determine how effectively the designs meet the stipulated ecological goals, how AM technologies demonstrate their potential in comparison to conventional methods and the preference locations of these implementations.

The overview revealed that the dominant artificial reef implementation occurs in the Mediterranean and Atlantic Seas, both accounting for 24%. The remaining cases were in the Australian Sea (20%), the South Asia Sea (12%), the Persian Gulf and the Pacific Ocean, both with 8%, and the Indian Sea with 4% of all the cases studied. It was concluded that fused filament fabrication, binder jetting and material extrusion represent the main AM processes used to build artificial reefs. Cementitious materials, ceramics, polymers and geopolymer formulations were used, incorporating aggregates from mineral residues, biological wastes and pozzolan materials, to reduce environmental impacts, promote the circular economy and be more beneficial for marine ecosystems. The evaluation ranking assessed how well their design and materials align with their ecological goals, demonstrating that five cases were ranked with high effectiveness, ten projects with moderate effectiveness and one case with low effectiveness.

AM represents an innovative method for marine restoration and management. It offers a rapid prototyping technique for design validation and enables the creation of highly complex shapes for habitat diversification while incorporating a diverse range of materials to benefit environmental and marine species’ habitats.