Lewis meets Brouwer: constructive strict implication

C. I. Lewis invented modern modal logic as a theory of "strict implication". Over the classical propositional calculus one can as well work with the unary box connective. Intuitionistically, however, the strict implication has greater expressive power than the box and allows to make distinctions invisible in the ordinary syntax. In particular, the logic determined by the most popular semantics of intuitionistic K becomes a proper extension of the minimal normal logic of the binary connective. Even an extension of this minimal logic with the "strength" axiom, classically near-trivial, preserves the distinction between the binary and the unary setting. In fact, this distinction and the strong constructive strict implication itself has been also discovered by the functional programming community in their study of "arrows" as contrasted with "idioms". Our particular focus is on arithmetical interpretations of the intuitionistic strict implication in terms of preservativity in extensions of Heyting's Arithmetic.Comment: Our invited contribution to the collection "L.E.J. Brouwer, 50 years later

Evolving into a Regional Innovation System: How Governance impact on Innovation in Shenzhen and Dongguan, China?

Governance constitutes elementary supportive infrastructure for regional innovation systems. This paper extends the evolutionary lens of governance into initial industrialization phase and examines the impact of their evolution into regional innovation systems on fostering innovation activities. Drawing on the empirical substances in Shenzhen and Dongguan, China, a path-dependent nature of institutional design on supporting innovation has been discovered. The paper shows that the dirigiste globalized production system in Shenzhen in 1980s has gradually evolved to a higher level of interactive regional innovation system than the grassroots globalized production system in Dongguan, where innovation is still passively managed by global players. Finally, policy implication is discussed for the construction of regional innovation systems under different governance modalities in the initial industrialization phase.ego-networks, geographical proximity, innovation performance, knowledge networks, technological relatedness

The Medical Treatment of Depression, 1991-1996: Productive Inefficiency, Expected Outcome Variations, and Price Indexes

We examine the price of treating episodes of acute phase major depression over the 1991-1996 time period. We combine data from a large retrospective medical claims data base (MarketScanTM, from the MedStat Group) with clinical literature and expert clinical opinion elicited from a two-state Delphi procedure. This enables us to construct a variety of treatment price indexes that include variations over time in the proportion of off-frontier' production, as well as the corresponding variations in expected treatment outcomes. We also incorporate the fact that the no treatment option ( waiting list') frequently results in spontaneous remission of depressive symptoms. We find that in general the incremental cost of successfully treating an episode of acute phase major depression has generally fallen over the 1991-96 time period. Based on hedonic regression equations that account for the effects of changing patient mix, we find price reductions that range from about -1.66% to -2.13% per year. An implication of this is that, since expenditures on depression are thought to be increasing since at least 1991, the source of the spending increases is volume (quantity) increases, and not price increases.

Strengthening agricultural education and training in Sub-Saharan Africa from an innovation systems perspective: Case studies of Ethiopia and Mozambique

"This paper examines the role of postsecondary agricultural education and training (AET) in Sub-Saharan Africa in the context of the region's agricultural innovation systems. Specifically, the paper looks at how AET in Sub-Saharan Africa can contribute to agricultural development by strengthening innovative capabilities, or the ability to introduce new products and processes that are socially or economically relevant to smallholder farmers and other agents in the agricultural sector. Using AET in Ethiopia and Mozambique as case studies, the paper argues that while AET is conventionally viewed in terms of its role in building human and scientific capital, it also has a vital role to play in building the capacity of organizations and individuals to transmit and adapt new applications of existing information, new products and processes, and new organizational cultures and behaviors. The paper emphasizes the importance of improving AET systems by strengthening the innovative capabilities of AET organizations and professionals; changing organizational cultures, behaviors, and incentives; and building innovation networks and linkages. The paper draws on two main sources of information: the emerging literature on innovation systems in developing-country agriculture, and data gathered from secondary sources and semi-structured key informant interviews conducted in Ethiopia and Mozambique in late 2006. The paper offers several recommendations that can contribute to enhancing the effectiveness of AET's contribution to agricultural innovation and development. Key reforms include aligning the mandates of AET organizations with national development aspirations by promoting new educational programs that are more strategically attuned to the different needs of society; inducing change in the cultures of AET organizations through the introduction of educational programs and linkages beyond the formal AET system; and strengthening individual and organizational capacity by improving incentives to forge stronger linkages between AET and diverse user communities, knowledge sources, and private industry." - from authors' abstract.Agricultural education and training, Innovation systems, Sub-Saharan Africa, case studies, Small farmers, agricultural sector,