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91.
Despite its worldwide success, the innovation systems approach is often criticised for being theoretically underdeveloped. This paper aims to contribute to the conceptual and methodological basis of the (technological) innovation systems approach. We propose an alteration that improves the analysis of dynamics, especially with respect to emerging innovation systems. We do this by expanding on the technological innovation systems and system functions literature, and by employing the method of ‘event history analysis’. By mapping events, the interactions between system functions and their development over time can be analysed. Based on this it becomes possible to identify forms of positive feedback, i.e. cumulative causation. As an illustration of the approach, we assess the biofuels innovation system in The Netherlands as it evolved from 1990 to 2007.  相似文献   
92.
MARKET STRUCTURE, PROGRAM DIVERSITY, AND RADIO AUDIENCE SIZE   总被引:1,自引:0,他引:1  
This paper examines the relationships among radio station listenership, the number of program formats, and the number of stations. These relationships are statistically significant and consistent with theory, but the interrelationships are numerically small. The results imply that proposals by the federal Communications Commission and Congress to relax ownership restrictions must induce substantial changes in station numbers in order to noticeably increase programming diversity. Merely modest changes in these numbers will have only small diversity effects. The paper's results also imply that merely mandating the number of formats in a market may not be in the interests of listeners.  相似文献   
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95.
The amount and type of economic-education training teachers receive have predictable effects on the teachers' optimism about the future of the American economic system.  相似文献   
96.
Sub‐Saharan African countries have traditionally lagged the rest of the developing world in terms of overall trade relative to gross domestic product. But, there is growing interest among these countries to initiate trade policies and improve quality of institutions as a way to promote trade and boost foreign direct investment. This article extends the gravity model of trade to include proxies for trade reform policy and institutional quality among the 15 countries of the Economic Community of West African States (ECOWAS) for data spanning 1984–2006. Alternative methods of estimation based on ordinary least squares, Heckman two‐step procedure, and Poisson pseudo‐maximum likelihood produce predictions that are consistent with the standard gravity model. They further highlight the evidence of restrictive trade policies and weak institutions that contribute to the failure of ECOWAS countries to boost bilateral trade. (JEL F13, F15, O19, O55)  相似文献   
97.
Abstract

Objectives: Atrial fibrillation (AF) is the most common arrhythmia and a major marker of ischemic stroke risk. Early detection is crucial and, once diagnosed, anticoagulation therapy can be initiated to reduce stroke risk. The aim of this study was to assess the cost-effectiveness of employing an insertable cardiac monitor (ICM), BIOMONITOR, for the detection of AF compared to standard of care (SoC) ECG and Holter monitoring in patients with cryptogenic stroke, that is, stroke of unknown origin and where paroxysmal, silent AF is suspected.

Materials and methods: A Markov model was developed which consisted of five main health states reflecting the potential lifetime evolution of the AF disease: post cryptogenic stroke (index event), subsequent mild, moderate and severe stroke, and death. Sub-states were included to track a patient’s AF diagnostic status and the use of antiplatelet or anticoagulant therapy. AF detection was assumed to result in a treatment switch from aspirin to anticoagulants, except among those with a history of major bleeding. Detection yield and accuracy, clinical actions and treatment effects were derived from the literature and validated by an expert clinician. All relevant costs from a US Medicare perspective were included.

Results and conclusions: An ICM-based strategy was associated with a reduction of 37 secondary ischemic strokes per 1000 patients monitored compared with SoC. Total per-patient costs with an ICM were higher (US$90,052 vs. US$85,157) although stroke-related costs were reduced. The use of an ICM was associated with a base-case incremental cost-effectiveness ratio of US$18,487 per life year gained compared with SoC and US$25,098 per quality-adjusted life year gained, below established willingness-to-pay thresholds. The conclusions were found to be robust over a range of input values. From a US Medicare perspective the use of a BIOMONITOR ICM represents a cost-effective diagnostic strategy for patients with cryptogenic stroke and suspected AF.  相似文献   
98.
Civilisations are imagined, ratherm than real, and nations undergoing identity crises typically represent themselves through multiple civilisational visions. Scholars of geopolitics can hardly understand foreign policy without analysing those visions and social contexts, in which they rise and fall. This article selects for analysis three distinct civilisational ideas of Russia – “West,” “Eurasia” and “Euro-East” – associated with Boris Yeltsin, Yevgeni Primakov and Vladimir Putin, respectively. Russia's foreign policy is best understood as reflecting those civilisational ideas rather than merely material power conditions.  相似文献   
99.
This paper investigates the relationship between patents and research and development expenditures using new longitudinal patent data at the firm level for the U.S. manufacturing sector from 1982 to 1992. The paper also develops a new class of count panel data models based on series expansion of the distribution of individual effects. Estimation results from various distributed lag and dynamic multiplicative panel count data models show that the contemporaneous relationship between patenting and R&D expenditures continues to be strong, accounting for over 60% of the total R&D elasticity. The lag effects are higher than have previously been found for the 1970s data. We would like to thank Chris Bollinger, Bronwyn Hall and Paula Stephan for useful comments on the previous version of the paper. Earlier versions were presented at the 11th International Conference on Panel Data, Texas A&M University, the Midwest Econometrics Group Meeting, and the Annual Conference of the Southern Economic Association.  相似文献   
100.
This study empirically examines the business cycle behaviour of public consumption and its main components, the public wage bill (including its breakdown into compensation per employee and public employment) and intermediate consumption, in the euro area aggregate, euro area countries and a group of selected non-euro area Organization for Economic Co-operation and Development (OECD) countries (Denmark, Sweden, the UK, Japan and the US). It looks across a large number of variables and methods, using annual data from 1960 to 2005. It finds robust evidence supporting that public consumption, wages and employment co-move with the business cycle in a pro-cyclical manner with 1–2 year lags, notably for the euro area aggregate and euro area countries. The findings reflect mainly the correlation between cyclical developments, but also point to an important role of pro-cyclical discretionary fiscal policies.  相似文献   
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