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In the treatment of an intracranial aneurysm with the flow diverter, the combined use of coil embolization can help promote subsequent progressive thrombosis within the aneurysm sac and reduce the risk of delayed aneurysm rupture. This study retrospectively reviewed outcomes of patients who had undergone the Pipeline Embolization Device (PED) with adjunctive coil embolization (PED/coil) at a single center to determine its safety and efficiency. Patients with internal carotid artery aneurysms following an intradural component were selected for PED/coil between 2015 and 2020. All patients were premedicated with dual antiplatelet therapy of aspirin plus clopidogrel or prasugrel. A minimal number of PEDs were deployed, with coils inserted using a stent-jail technique, avoiding dense packing. A total of 46 aneurysms (43 patients; median dome size, 11.6 mm; median neck width, 6.3 mm) were treated with PED/coil. The median volume embolization ratio was 14.8%. The degree of angiographic filling at the 6-month and latest angiography showed complete occlusion in 60.5% (26/43) and 70.5% (31/44), respectively. Small ( 10 mm) aneurysms achieved a higher complete occlusion rate in the early period; a lower cumulative incidence of aneurysm occlusion was observed in large and giant (≥ 10 mm) aneurysms (P = .024). The median clinical follow-up was 22 months, and no aneurysm ruptures occurred. Favorable clinical outcomes were achieved, with permanent neurological morbidity of 4.7% and no mortality. PED/coil demonstrated a high angiographic occlusion rate at an early stage. Loosely packed coils are sufficient to obliterate aneurysms effectively.

This is the peer reviewed version of the following article: Horii, R. & Ono, Y. (2021) Financial crisis and slow recovery with Bayesian learning agents. International Journal of Economic Theory, 1– 29, which has been published in final form at https://doi.org/10.1111/ijet.12322. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited., In a simple continuous-time model where the learning process affects the willingness to hold liquidity, we provide an intuitive explanation of business cycle asymmetry and postcrisis slow recovery. When observing a liquidity shock, individuals rationally increase their subjective probability of re-encountering it. It leads to an upward jump in liquidity preference and a discrete fall in consumption. Conversely, as a period without shocks continues, they gradually decrease the subjective probability, reduce liquidity preference, and increase consumption. The recovery process is particularly slow after many shocks are observed within a short period because people do not easily change their pessimistic view.

Background An exchange maneuver is useful for the delivery of devices to target vessels. However, hemorrhagic complications can occur due to vessel perforation during an exchange maneuver. In addition, the exchange is often challenging due to unfavorable anatomy. Center Wire is an exchange-length wire with a nondetachable stent that was developed to improve navigation and stability during exchange maneuvers. The aim of this study is to investigate the safety and efficacy of Center Wire of the anchor wire technique during neuroendovascular treatment. Methods Ten patients with intracranial aneurysms were treated after signing a Certified Review Board-approved consent. Anchor wire technique was used in all patients to navigate catheters to the target vessel for aneurysm treatment. Results Anchor wire technique was successfully applied in all 10 cases using Center Wire. One device-related incident of vasospasm occurred which was asymptomatic. No device-related dissection, perforation, or thromboembolic events occurred. One patient had intraoperative aneurysm rupture during coil placement which was treated immediately without clinical consequences. Two patients had postoperative ischemic strokes due to thrombotic occlusion of branches originating from the aneurysm which were unrelated to the device. Conclusions This first-in-human trial of Center Wire demonstrated the safety and efficacy of the anchor wire technique for neuroendovascular treatment in a strictly regulated prospective registry trial.

Background Copolymer (Onyx) embolization is an effective treatment for dural arteriovenous fistula (dAVF), however, some dAVFs have multiple, high-flow feeding vessels, resulting in insufficient embolization. For the treatment of such patients, we have developed a novel flow-control technique, the ‘damp-and-push technique’. The purpose of this study was to evaluate the technical efficiency and safety of this technique. Methods Seven patients who had been diagnosed with intracranial dAVF were treated by transarterial Onyx embolization using the damp-and-push technique between 2016 and 2019. This technique was designed to reduce blood flow to the shunt site using a balloon catheter in the major feeding vessel other than the one injected with Onyx, leading to better Onyx penetration and enabling more controlled embolization of complex dAVFs. Retrospectively collected data were reviewed to assess the occlusion rates and clinical outcomes. Results The dAVF was at a transverse sinus-sigmoid sinus junction in four patients, in the superior sagittal sinus in two, and in the tentorium in one. Five cases were Cognard type Ⅱb and two cases were Cognard type Ⅳ. All the patients were treated by transarterial Onyx injection via the main feeding vessel, combined with flow reduction in the other main feeding vessel using a balloon catheter. Complete occlusion was achieved in six patients and elimination of cerebral venous reflux was achieved in all the patients. There were no immediate or delayed post-interventional complications. Conclusions Transarterial Onyx embolization of dAVF using the damp-and-push technique is safe and yields a high complete occlusion rate.

We prove a generalized, multi-factor version of the Uzawa steady-state growth theorem. In the two-factor case, the theorem implies that a neoclassical growth model cannot be simultaneously consistent with empirical evidence on both capital-augmenting technical change and the elasticity of substitution between labor and reproducible capital. In the multi-factor case, balanced growth with capital-augmenting technical change is possible as long as capital has a unitary elasticity of substitution with any single non-reproducible factor, increasing the likelihood that neoclassical models can be consistent with empirical findings. To illustrate the importance of this result, we also build a three-factor growth model with endogenous and directed technical change and show that is has a stable balanced growth path with a strictly positive rate of capital-augmenting technical change.

Using an endogenous growth model with physical and human capital accumulation, this paper considers the sustainability of economic growth when the use of a polluting input (e.g., fossil fuels) intensifies the risk of capital destruction through natural disasters. We find that growth is sustainable only if the tax rate on the polluting input increases over time. The long-term rate of economic growth follows an inverted V-shaped curve relative to the growth rate of the environmental tax, and it is maximized by the least aggressive tax policy of those that asymptotically eliminate the use of polluting inputs. Unavailability of insurance can accelerate or decelerate the growth-maximizing speed of the tax increase depending on the relative significance of the risk premium and precautionary savings effects. Welfare is maximized under a milder environmental tax policy, especially when the pollutants accumulate gradually.

This paper examines the effect of the timing of childbirth on capital accumulation and welfare in a simple overlapping generations model, where each agent lives for four periods and works for two periods. We show that delayed childbearing not only reduces population, but also generates fluctuations in the age composition of workers in the labour force. This causes the aggregate saving rate to fluctuate, which leads to cycles in the capital--labour ratio. When all agents delay childbearing, we analytically show that both the capital--labour ratio and the welfare of all agents can fall in the long run, despite the population decline. When a fraction of agents delay childbearing, it has differential welfare effects on agents depending on their positions in the demographic cycles. The effects of lower lifetime fertility and technological progress are also examined. Copyright 2013 Oxford University Press 2012 All rights reserved, Oxford University Press.

This paper develops a theory of endogenous growth cycles focusing on the interaction between consumers' desire to satisfy an indefinite range of wants and firms' incentive to utilize knowledge from past production experiences. We show that firms endogenously form a number of distinguishable industries as accumulated knowledge induces them to agglomerate in the technology space. Knowledge accumulation in existing industries reduces production costs, but, as the diminishing returns from learning sets in, some firms start to adopt previously unexplored technologies so that their new goods fit consumers' unsatisfied wants and attract large demand. Thus, sporadic emergence of new industries generates growth cycles, where both the timing and the new technology to be adopted are endogenously determined. New industries based on new technology reduce the rate of per capita GDP growth in the initial phase, but nonetheless are indispensable for sustained economic growth in the long run.

A mutual link between poverty and environmental degradation is examined in an overlapping generations model. Environmental quality affects labor productivity and wealth dynamics, whereas wealth distribution determines the degree to which agents rely on technology that has a large environmental load, and therefore the evolution of environmental quality. This interaction creates a “poverty–environment trap,” where a deteriorated environment lowers income, which, in turn, accelerates environmental degradation. We show that greater wealth heterogeneity is the key to escaping from the poverty–environment trap, although it can have negative effects on both the environment and output when not in the trap.

Using a simple overlapping generations model, this note shows that an improvement in the efficiency of human capital investment decreases the net income of the young household while increasing that of the old. Without compensating redistribution, it deteriorates lifetime utilities of all generations except for the initial old households.

This paper examines the implications of the mutual causality between environmental quality and economic growth. While economic growth deteriorates the environment through increasing amounts of pollution, the deteriorated environment in turn limits the possibility of further economic growth. In a less developed country, this link, which we call “limits to growth,” emerges as the “poverty-environment trap,” which explains the persistent international inequality both in terms of income and environment. This link also threatens the sustainability of the world’s economic growth, particularly when the emission of greenhouse gases raises the risk of natural disasters. Stronger environmental policies are required to overcome this link. While there is a trade-off between the environment and growth in the short run, we show that an appropriate policy can improve both in the long run.

This paper constructs an overlapping generations model with a frictional labor market to explain persistent low education in developing countries. When parents are uneducated, their children often face difficulties in finishing school and therefore are likely to remain uneducated. Moreover, if children expect that other children of the same generation will not receive an education, they expect that firms will not create enough jobs for educated workers, and thus are further discouraged from schooling. These intergenerational and intragenerational mechanisms reinforce each other, creating a serious poverty trap. Escape from the trap requires the well-organized and combined implementation of a subsidy for schooling, the provision of free education, support for disadvantaged children, and public awareness programs.

This paper presents an overlapping generations model with technology choice and imperfect financial markets, and examines the evolution of the income distribution in economic development. The model shows that improvements in financial infrastructure facilitate economic development both by raising the aggregate capital–labor ratio and by causing a technological shift to more capital-intensive technologies. Although a higher capital–labor ratio under a given technology reduces inequality, a technological shift can lead to a concentration of economic rents among a smaller number of agents. We derive the condition under which an improvement in financial infrastructure actually decreases the average utility of agents.

This paper constructs an overlapping generations model of search equilibrium that analyzes intergenerational and coordination traps simultaneously. When parents are uneducated, their children often face difficulty in finishing school, and therefore likely to remain uneducated. In addition, if children expect that other children of the same generation do not receive education, they anticipate that firms will not create enough jobs for educated and thus are discouraged from schooling. These two mechanisms of poverty trap reinforce each other-creating a dual poverty trap. Escaping from the trap requires a combined, not separate, implementation of financial assistance for schooling and policies for changing agents f expectation.

Using an endogenous growth model with physical and human capital accumulation, this paper considers the sustainability of economic growth when the use of a polluting input (e.g., fossil fuels) intensifies the risk of capital destruction through natural disasters. We find that growth is sustainable only if the tax rate on the polluting input increases over time. The long-term rate of economic growth follows an inverted V-shaped curve relative to the growth rate of the environmental tax, and it is maximized by the least aggressive tax policy of those that asymptotically eliminate the use of polluting inputs. Unavailability of insurance can accelerate or decelerate the growth-maximizing speed of the tax increase depending on the relative significance of the risk premium and precautionary savings effects. Welfare is maximized under a milder environmental tax policy, especially when the pollutants accumulate gradually.

This paper constructs a model that describes inflation cycles and prolonged depression as generated by the learning behavior of households who face a random liquidity shock in which money is needed. Households update the subjective probability of the shock based on the observation and change their liquidity preference accordingly. In this setting, we first derive a stationary cycles under perfect price adjustment, which is characterized by periods of gradual inflation and sudden sporadic falls of the price level. When the nominal stickiness is introduced, the liquidity shock is followed by a period of depression in which unemployment exists and deflation occurs gradually. Depression is deep and prolonged when the economy has experienced a long period of boom before encountering a liquidity shock.

This paper examines the growth effects of intellectual property right (IPR) protection in a quality-ladder model of endogenous growth. Stronger IPR protection, which reduces the imitation probability, increases the reward for innovation. However, stronger protection also gradually reduces the number of competitive sectors, in which innovation is easier than in monopolistic sectors. With free entry to R&D, the number of researchers in each remaining competitive sector increases, but the concentration of R&D activity raises the possibility of unnecessary duplication of innovation, thereby hindering growth. Consequently, imperfect rather than perfect protection maximizes growth. Welfare and scale effects are also examined.

This paper develops a theory of endogenous growth cycles focusing on the interaction between consumers f desire to satisfy an indefinite range of wants and firms f incentive to utilize knowledge from past production experiences. We show that firms endogenously form a number of distinguishable industries as accumulated knowledge induces them to agglomerate in the technology space. Knowledge accumulation in existing industries reduces production costs, but, as the diminishing returns from learning sets in, some firms start to adopt previously unexplored technologies so that their new goods fit consumers f unsatisfied wants and attract large demand. Thus, sporadic emergence of new industries generates growth cycles, where both the timing and the new technology to be adopted are endogenously determined. New industries based on new technology reduce the rate of per capita GDP growth in the initial phase, but nonetheless are indispensable for sustained economic growth in the long run.

This paper examines a mechanism of liquidity-preference fluctuations caused by people's learning behavior. % about the frequency of a liquidity shock. When observing a financial shock, they rationally update their belief so that the subjective probability of encountering it again is higher, immediately raise liquidity preference and reduce consumption. As a period without the shock lasts after that, they gradually decrease the subjective probability, lower liquidity preference and increase consumption. Particularly, when the shock is observed many times in succession, recovery is first slow because people do not easily change their pessimistic view, then gradually accelerates, and eventually slows down as they become fully optimistic.

This paper presents an overlapping generations model with technology choice and credit market imperfections, in order to investigate a possible source of underdevelopment. The model shows that a better financial infrastructure that provides stronger enforcement of contracts facilitates the development of financial markets, which, in turn, enables firms to switch to more productive and capital-intensive technologies, thereby promoting economic development. In the presence of credit rationing, however, this technological switch widens inequality. Therefore, risk-averse agents would not be willing to improve the financial infrastructure to the level at which the technological switch occurs, resulting in a development trap. A remedy is to facilitate small firms f adoption of the currently used technology rather than the new one.

This paper examines a mechanism of liquidity-preference fluctuations caused by changes in people's belief about a random liquidity shock. When observing the shock, they rationally update their belief so that the shock probability is higher; consequently they raise liquidity preference and reduce consumption. As the period without the shock lasts, they become more optimistic so that they gradually lower liquidity preference and increase consumption. The recovery pattern depends on the realized frequency of the shock: when the shock occurs many times in succession, the consumption recovery is first slow, gradually accelerates and eventually slows down, tracing an 'S'-shaped curve.

Using an overlapping generations model, this note shows that an improvement in the efficiency of human capital production decreases the net income of the young household while increasing that of the old. Without compensating redistribution, it deteriorates lifetime utilities of all generations except for the initial old households.

This paper examines the economic growth effects of limited availability of higher education in a simple endogenous growth model with overlapping generations. With limited availability, the scarcity of human capital keeps its price high and distributes a larger share of the aggregate output to young households. Under certain conditions, it leads to greater aggregate savings in each period, thereby enabling the economy to grow faster than without any limitation. In such cases, an excessive expansion in the availability causes a temporary boom followed by a serious deficiency in investible funds, resulting in a substantial slowdown in economic growth.

This paper constructs a growth model in which monopolistically competing firms choose the characteristic of their own product from an unbounded product space. While consumers wish to satisfy various needs by purchasing a diverse range of goods, production costs are lower for those goods that are more similar to existing ones because of spillover effects in the learning-bydoing process. The dynamic interaction of these centrifugal and centripetal forces on the product space leads to sporadic emergence and disappearance of industries, which is a source of cyclical fluctuations in the macroeconomic growth rate.