Suchergebnisse

We analyze financial markets in which agents face differential constraints on the set of assets in which they can trade. In particular, the assets available to each agent span a partition of the state space, which can be strictly coarser than the partition spanned by the assets available in the market. We first show that the existence of differential constraints has an impact on prices and allocations as compared to a complete financial market with unconstrained agents. We consider the implications for survival, taking the work of Blume and Easley (2006) as a starting point. We show that whenever agents have identical correct beliefs and equal discount factors, and their partitions are nested, all agents survive. When agents have heterogeneous beliefs, differential constraints may allow agents with wrong beliefs to survive. Provided constraints are relevant (in a sense we define more precisely), the condition for an agent to survive is that his survival index is at least as large as that of the agents with finer partitions. We also study the impact of deregulation (an increase in the set of assets available to some agents). Unless the agent can adopt beliefs that are closer to the truth on the newly refined partition than those of less constrained agents, increasing his opportunities for trade might harm his chances for survival.

We analyze financial markets in which agents face differential constraints on the set of assets in which they can trade. In particular, the assets available to each agent span a partition of the state space, which can be strictly coarser than the partition spanned by the assets available in the market. We first show that the existence of differential constraints has an impact on prices and allocations as compared to a complete financial market with unconstrained agents. We consider the implications for survival, taking the work of Blume and Easley (2006) as a starting point. We show that whenever agents have identical correct beliefs and equal discount factors, and their partitions are nested, all agents survive. When agents have heterogeneous beliefs, differential constraints may allow agents with wrong beliefs to survive. Provided constraints are relevant (in a sense we define more precisely), the condition for an agent to survive is that his survival index is at least as large as that of the agents with finer partitions. We also study the impact of deregulation (an increase in the set of assets available to some agents). Unless the agent can adopt beliefs that are closer to the truth on the newly refined partition than those of less constrained agents, increasing his opportunities for trade might harm his chances for survival.

Many economists have long held that market failures create a gap between social and private returns to Research and Development (R&D), thereby limiting private incentives to invest in R&D. However, this common belief that firms significantly underinvest in R&D is increasingly being challenged, leading the rationale behind public support for private R&D to be questioned. In this paper, we attempt to clarify the perspectives of two sources : the theoretical literature on endogenous growth, and its recent developments in integrating a geographical dimension, and the empirical literature that measures the social returns to R&D in relation to the private returns. Ultimately, we are able to clearly distinguish among different types of market failures and compare their relative impact on the gap between the private and social returns to R&D. Two main conclusions are reached. First, systematic firm underinvestment in R&D is not demonstrated. Second, even though instances of underinvestment do occur, they are mainly explained by surplus appropriability problems rather than by knowledge externalities. This suggests the need for a new policy mix that employs more demand-oriented instruments and is more concentrated on identifying efficient allocations among activities rather than merely increasing global private R&D investment.

Many economists have long held that market failures create a gap between social and private returns to Research and Development (R&D), thereby limiting private incentives to invest in R&D. However, this common belief that firms significantly underinvest in R&D is increasingly being challenged, leading the rationale behind public support for private R&D to be questioned. In this paper, we attempt to clarify the perspectives of two sources : the theoretical literature on endogenous growth, and its recent developments in integrating a geographical dimension, and the empirical literature that measures the social returns to R&D in relation to the private returns. Ultimately, we are able to clearly distinguish among different types of market failures and compare their relative impact on the gap between the private and social returns to R&D. Two main conclusions are reached. First, systematic firm underinvestment in R&D is not demonstrated. Second, even though instances of underinvestment do occur, they are mainly explained by surplus appropriability problems rather than by knowledge externalities. This suggests the need for a new policy mix that employs more demand-oriented instruments and is more concentrated on identifying efficient allocations among activities rather than merely increasing global private R&D investment.

Many economists have long held that market failures create a gap between social and private returns to Research and Development (R&D), thereby limiting private incentives to invest in R&D. However, this common belief that firms significantly underinvest in R&D is increasingly being challenged, leading the rationale behind public support for private R&D to be questioned. In this paper, we attempt to clarify the perspectives of two sources : the theoretical literature on endogenous growth, and its recent developments in integrating a geographical dimension, and the empirical literature that measures the social returns to R&D in relation to the private returns. Ultimately, we are able to clearly distinguish among different types of market failures and compare their relative impact on the gap between the private and social returns to R&D. Two main conclusions are reached. First, systematic firm underinvestment in R&D is not demonstrated. Second, even though instances of underinvestment do occur, they are mainly explained by surplus appropriability problems rather than by knowledge externalities. This suggests the need for a new policy mix that employs more demand-oriented instruments and is more concentrated on identifying efficient allocations among activities rather than merely increasing global private R&D investment.

Many economists have long held that market failures create a gap between social and private returns to Research and Development (R&D), thereby limiting private incentives to invest in R&D. However, this common belief that firms significantly underinvest in R&D is increasingly being challenged, leading the rationale behind public support for private R&D to be questioned. In this paper, we attempt to clarify the perspectives of two sources : the theoretical literature on endogenous growth, and its recent developments in integrating a geographical dimension, and the empirical literature that measures the social returns to R&D in relation to the private returns. Ultimately, we are able to clearly distinguish among different types of market failures and compare their relative impact on the gap between the private and social returns to R&D. Two main conclusions are reached. First, systematic firm underinvestment in R&D is not demonstrated. Second, even though instances of underinvestment do occur, they are mainly explained by surplus appropriability problems rather than by knowledge externalities. This suggests the need for a new policy mix that employs more demand-oriented instruments and is more concentrated on identifying efficient allocations among activities rather than merely increasing global private R&D investment.

Many economists have long held that market failures create a gap between social and private returns to Research and Development (R&D), thereby limiting private incentives to invest in R&D. However, this common belief that firms significantly underinvest in R&D is increasingly being challenged, leading the rationale behind public support for private R&D to be questioned. In this paper, we attempt to clarify the perspectives of two sources : the theoretical literature on endogenous growth, and its recent developments in integrating a geographical dimension, and the empirical literature that measures the social returns to R&D in relation to the private returns. Ultimately, we are able to clearly distinguish among different types of market failures and compare their relative impact on the gap between the private and social returns to R&D. Two main conclusions are reached. First, systematic firm underinvestment in R&D is not demonstrated. Second, even though instances of underinvestment do occur, they are mainly explained by surplus appropriability problems rather than by knowledge externalities. This suggests the need for a new policy mix that employs more demand-oriented instruments and is more concentrated on identifying efficient allocations among activities rather than merely increasing global private R&D investment.

Many economists have long held that market failures create a gap between social and private returns to Research and Development (R&D), thereby limiting private incentives to invest in R&D. However, this common belief that firms significantly underinvest in R&D is increasingly being challenged, leading the rationale behind public support for private R&D to be questioned. In this paper, we attempt to clarify the perspectives of two sources : the theoretical literature on endogenous growth, and its recent developments in integrating a geographical dimension, and the empirical literature that measures the social returns to R&D in relation to the private returns. Ultimately, we are able to clearly distinguish among different types of market failures and compare their relative impact on the gap between the private and social returns to R&D. Two main conclusions are reached. First, systematic firm underinvestment in R&D is not demonstrated. Second, even though instances of underinvestment do occur, they are mainly explained by surplus appropriability problems rather than by knowledge externalities. This suggests the need for a new policy mix that employs more demand-oriented instruments and is more concentrated on identifying efficient allocations among activities rather than merely increasing global private R&D investment.

Many economists have long held that market failures create a gap between social and private returns to Research and Development (R&D), thereby limiting private incentives to invest in R&D. However, this common belief that firms significantly underinvest in R&D is increasingly being challenged, leading the rationale behind public support for private R&D to be questioned. In this paper, we attempt to clarify the perspectives of two sources : the theoretical literature on endogenous growth, and its recent developments in integrating a geographical dimension, and the empirical literature that measures the social returns to R&D in relation to the private returns. Ultimately, we are able to clearly distinguish among different types of market failures and compare their relative impact on the gap between the private and social returns to R&D. Two main conclusions are reached. First, systematic firm underinvestment in R&D is not demonstrated. Second, even though instances of underinvestment do occur, they are mainly explained by surplus appropriability problems rather than by knowledge externalities. This suggests the need for a new policy mix that employs more demand-oriented instruments and is more concentrated on identifying efficient allocations among activities rather than merely increasing global private R&D investment.

Many economists have long held that market failures create a gap between social and private returns to Research and Development (R&D), thereby limiting private incentives to invest in R&D. However, this common belief that firms significantly underinvest in R&D is increasingly being challenged, leading the rationale behind public support for private R&D to be questioned. In this paper, we attempt to clarify the perspectives of two sources : the theoretical literature on endogenous growth, and its recent developments in integrating a geographical dimension, and the empirical literature that measures the social returns to R&D in relation to the private returns. Ultimately, we are able to clearly distinguish among different types of market failures and compare their relative impact on the gap between the private and social returns to R&D. Two main conclusions are reached. First, systematic firm underinvestment in R&D is not demonstrated. Second, even though instances of underinvestment do occur, they are mainly explained by surplus appropriability problems rather than by knowledge externalities. This suggests the need for a new policy mix that employs more demand-oriented instruments and is more concentrated on identifying efficient allocations among activities rather than merely increasing global private R&D investment.

The "Geography of Innovation" is based on the desire to give empirical foundations to the explanations behind the pronounced spatial polarisation of the innovation activities. It focuses on an attempt to measure the spatial dimension of knowledge externalities, in order to reveal their role in the organisation of research systems. The aim of this paper is to survey this empirical literature in order to highlight the main results interesting for the innovation policy. This analysis emphasises one main role of technology policy : supporting the institutions which generate knowledge and learning. These are found at various territorial levels, especially within the European Union. Here attention is drawn to the regional intervention level.

The "Geography of Innovation" is based on the desire to give empirical foundations to the explanations behind the pronounced spatial polarisation of the innovation activities. It focuses on an attempt to measure the spatial dimension of knowledge externalities, in order to reveal their role in the organisation of research systems. The aim of this paper is to survey this empirical literature in order to highlight the main results interesting for the innovation policy. This analysis emphasises one main role of technology policy : supporting the institutions which generate knowledge and learning. These are found at various territorial levels, especially within the European Union. Here attention is drawn to the regional intervention level.