Social Security Systems, Human Capital, and Growth in a Small Open Economy

We consider a small open economy in which the level of public education funding is determined by popular vote. We show that growth can be enhanced by the introduction of pay-as-you-go pensions even if the growth rate of aggregate wages falls short of the interest rate. The reason is that the PAYG system allows future retirees to partially internalize positive externalities of public education due to the positive effect of higher future labor productivity on their pension benefits. The majority support for education funding will be especially strong when the PAYG benefit formula is flat, i.e. progressively redistributive. This means that if a flat benefit PAYG pension system is in place then the economy will achieve the highest growth rate relative to the alternative pension system designs. We argue furthermore that while such PAYG pension system may be opposed by the majority of working individuals due to inferior returns to their pension contributions relative to a funded scheme, it is likely to be politically sustained by the coalition of retirees and lower income workers.pay-as-you-go pensions, social security, public education, growth, majority voting

Metformin, Sulfonylureas, or Other Antidiabetes Drugs and the Risk of Lactic Acidosis or Hypoglycemia

OBJECTIVE: Lactic acidosis has been associated with use of metformin. Hypoglycemia is a major concern using sulfonylureas. The aim of this study was to compare the risk of lactic acidosis and hypoglycemia among patients with type 2 diabetes using oral antidiabetes drugs. RESEARCH DESIGN AND METHODS: This study is a nested case-control analysis using the U.K.-based General Practice Research Database to identify patients with type 2 diabetes who used oral antidiabetes drugs. Within the study population, all incident cases of lactic acidosis and hypoglycemia were identified, and hypoglycemia case subjects were matched to up to four control patients based on age, sex, practice, and calendar time. RESULTS: Among the study population of 50,048 type 2 diabetic subjects, six cases of lactic acidosis during current use of oral antidiabetes drugs were identified, yielding a crude incidence rate of 3.3 cases per 100,000 person-years among metformin users and 4.8 cases per 100,000 person-years among users of sulfonylureas. Relevant comorbidities known as risk factors for lactic acidosis could be identified in all case subjects. A total of 2,025 case subjects with hypoglycemia and 7,278 matched control subjects were identified. Use of sulfonylureas was associated with a materially elevated risk of hypoglycemia. The adjusted odds ratio for current use of sulfonylureas was 2.79 (95% CI 2.23–3.50) compared with current metformin use. CONCLUSIONS: Lactic acidosis during current use of oral antidiabetes drugs was very rare and was associated with concurrent comorbidity. Hypoglycemic episodes were substantially more common among sulfonylurea users than among users of metformin.Merck SA, Lyon, Franc

Graph algebras and orbit equivalence

We introduce the notion of orbit equivalence of directed graphs, following Matsumoto’s notion of continuous orbit equivalence for topological Markov shifts. We show that two graphs in which every cycle has an exit are orbit equivalent if and only if there is a diagonal-preserving isomorphism between their C∗C∗-algebras. We show that it is necessary to assume that every cycle has an exit for the forward implication, but that the reverse implication holds for arbitrary graphs. As part of our analysis of arbitrary graphs EE we construct a groupoid G(C∗(E),D(E))G(C∗(E),D(E)) from the graph algebra C∗(E)C∗(E) and its diagonal subalgebra D(E)D(E) which generalises Renault’s Weyl groupoid construction applied to (C∗(E),D(E))(C∗(E),D(E)). We show that G(C∗(E),D(E))G(C∗(E),D(E)) recovers the graph groupoid GEGE without the assumption that every cycle in EE has an exit, which is required to apply Renault’s results to (C∗(E),D(E))(C∗(E),D(E)). We finish with applications of our results to out-splittings of graphs and to amplified graphs

An Interim Assessment of the U.S. Trade Policy of “Competitive Liberalization”

Since taking office the Administration of George W. Bush has pursued a trade policy known as Competitive Liberalization. This policy envisages a series of mutually-reinforcing steps to open markets abroad to U.S. companies, to strengthen market-oriented laws and regulations overseas, and to place the U.S. at the centre of the world trading system. Foreign and security policy considerations have influenced U.S. trade policymaking, perhaps more so than in the 1990s. To date the principal outcome of this policy has been the negotiation by the U.S. of numerous free trade agreements, mainly with developing countries individually or in subregional groupings. In addition to characterising this policy in detail, the principal purpose of this paper is to assess the logic underlying this approach to trade policymaking and whether Competitive Liberalization has begun to fulfil the promise spelt out for it at the beginning of this decade.United States, trade policy, commercial policy, Competitive Liberalization, WTO, regional trade agreements

Graph algebras and orbit equivalence

We introduce the notion of orbit equivalence of directed graphs, following Matsumoto's notion of continuous orbit equivalence for topological Markov shifts. We show that two graphs in which every cycle has an exit are orbit equivalent if and only if there is a diagonal-preserving isomorphism between their $C^*$-algebras. We show that it is necessary to assume that every cycle has an exit for the forward implication, but that the reverse implication holds for arbitrary graphs. As part of our analysis of arbitrary graphs $E$ we construct a groupoid $\mathcal{G}_{(C^*(E),\mathcal{D}(E))}$ from the graph algebra $C^*(E)$ and its diagonal subalgebra $\mathcal{D}(E)$ which generalises Renault's Weyl groupoid construction applied to $(C^*(E),\mathcal{D}(E))$. We show that $\mathcal{G}_{(C^*(E),\mathcal{D}(E))}$ recovers the graph groupoid $\mathcal{G}_E$ without the assumption that every cycle in $E$ has an exit, which is required to apply Renault's results to $(C^*(E),\mathcal{D}(E))$. We finish with applications of our results to out-splittings of graphs and to amplified graphs.Comment: 27 page

The Complexity of Reasoning for Fragments of Autoepistemic Logic

Autoepistemic logic extends propositional logic by the modal operator L. A formula that is preceded by an L is said to be "believed". The logic was introduced by Moore 1985 for modeling an ideally rational agent's behavior and reasoning about his own beliefs. In this paper we analyze all Boolean fragments of autoepistemic logic with respect to the computational complexity of the three most common decision problems expansion existence, brave reasoning and cautious reasoning. As a second contribution we classify the computational complexity of counting the number of stable expansions of a given knowledge base. To the best of our knowledge this is the first paper analyzing the counting problem for autoepistemic logic

Hidden and Uncontrolled - On the Emergence of Network Steganographic Threats

Network steganography is the art of hiding secret information within innocent network transmissions. Recent findings indicate that novel malware is increasingly using network steganography. Similarly, other malicious activities can profit from network steganography, such as data leakage or the exchange of pedophile data. This paper provides an introduction to network steganography and highlights its potential application for harmful purposes. We discuss the issues related to countering network steganography in practice and provide an outlook on further research directions and problems.Comment: 11 page