Relationship-Specific Sunk Costs and Exporter Decisions

Using macro-level trade data, we investigate how different types of sunk costs influence decisions of exporters. We find that exporters’ decisions reflect sensibly their desire to minimize the relationship-specific sunk costs. Specifically, exporters of differentiated products are more likely to reenter the export market than exporters of homogenous products. Also, the former are more likely to stay in the export market and exhibit more stability when doing so than the later. All of our findings are consistent with the view that relationship with their foreign partners matters more for trade in differentiated products than in homogenous ones.International Trade; Market Reentry, Market Exit, Networks; Sunk Costs; Transition Probability Matrix

Convergence of the Lasserre Hierarchy of SDP Relaxations for Convex Polynomial Programs without Compactness

The Lasserre hierarchy of semidefinite programming (SDP) relaxations is an effective scheme for finding computationally feasible SDP approximations of polynomial optimization over compact semi-algebraic sets. In this paper, we show that, for convex polynomial optimization, the Lasserre hierarchy with a slightly extended quadratic module always converges asymptotically even in the face of non-compact semi-algebraic feasible sets. We do this by exploiting a coercivity property of convex polynomials that are bounded below. We further establish that the positive definiteness of the Hessian of the associated Lagrangian at a saddle-point (rather than the objective function at each minimizer) guarantees finite convergence of the hierarchy. We obtain finite convergence by first establishing a new sum-of-squares polynomial representation of convex polynomials over convex semi-algebraic sets under a saddle-point condition. We finally prove that the existence of a saddle-point of the Lagrangian for a convex polynomial program is also necessary for the hierarchy to have finite convergence.Comment: 17 page

Regional differences in willingness to pay for organic vegetables

The concern about vegetable safety, together with a booming population and the rise of the middle class has made Vietnam become a potential market for organic vegetables. This paper investigates the determinants of willingness to pay (WTP) for organic vegetables in Hanoi, Vietnam with a particular attention to regional differences and the effect of risk perception. Using Contingent Valuation Method to analyze the data from a sample of 498 consumers in Hanoi, the paper shows that the perceived use values of organic vegetables, trust in organic labels, and disposable family income increased WTP for organic vegetables in both urban and rural regions.Though risk perception of conventional vegetables was high in both regions, such heightened risk perception just translated into the WTP in the rural region. In addition, the percentage of home-grown vegetables in the total vegetable consumption of the family influenced the WTP in the rural region only. Moreover, being an organic purchaser was positively related to the WTP in the urban region but not in the rural region. The paper also discusses three policy implications for Vietnam to boost the demand for organic food.fals

Preduals of semigroup algebras

For a locally compact group G, the measure convolution algebra M(G) carries a natural coproduct. In previous work, we showed that the canonical predual C 0(G) of M(G) is the unique predual which makes both the product and the coproduct on M(G) weak*-continuous. Given a discrete semigroup S, the convolution algebra ℓ 1(S) also carries a coproduct. In this paper we examine preduals for ℓ 1(S) making both the product and the coproduct weak*-continuous. Under certain conditions on S, we show that ℓ 1(S) has a unique such predual. Such S include the free semigroup on finitely many generators. In general, however, this need not be the case even for quite simple semigroups and we construct uncountably many such preduals on ℓ 1(S) when S is either ℤ+×ℤ or (ℕ,⋅)

Chiral Anomaly Effects and the BaBar Measurements of the γγ∗→π0\gamma\gamma^{*}\to \pi^{0} Transition Form Factor

The recent BaBar measurements of the $\gamma\gamma^{*}\to \pi^{0}$ transition form factor show spectacular deviation from perturbative QCD prediction for large space-like $Q^{2}$ up to $34\,\rm GeV^{2}$. When plotted against $Q^{2}$, $Q^{2}F(Q^{2})$ shows steady increase with $Q^{2}$ in contrast with the flat $Q^{2}$ behavior predicted by perturbative QCD, and at $34\,\rm GeV^{2}$ is more than 50% larger than the QCD prediction. Stimulated by the BaBar measurements, we revisit our previous paper on the cancellation of anomaly effects in high energy processes $Z^{0}\to \pi^{0}\gamma$, $e^{+}e^{-}\to \pi^{0}\gamma$ and apply our results to the $\gamma^{*}\gamma\to \pi^{0}$ transition form factor measured in the $e^{+}e^{-}\to e^{+}e^{-}\pi^{0}$ process with one highly virtual photon. We find that, the transition form factor $F(Q^{2})$ behaves as $(\frac{m^{2}}{Q^{2}})\times (\ln(Q^{2}/m^{2}))^{2}$ and produces a striking agreement with the BaBar data for $Q^{2}F(Q^{2})$ with $m=132\,\rm MeV$ which also reproduces very well the CLEO data at lower $Q^{2}$.Comment: v4, LaTeX, 8 pages, one figure, minor changes(references), to appear in Int. J. Mod. Phys.

The collective consciousness of Information Technology research: The significance and value of research projects. A. The views of IT researchers

This research seeks to reveal the different perceptual worlds in a research community, with the longterm intent of fostering increased understanding and hence collaboration. In the relatively new field of information technology (IT) research, available evidence suggests that a shared understanding of the research object or territory does not yet exist. This has led to the development of different perceptions amongst IT researchers of what constitutes significant and valuable research. A phenomenological approach is used to elicit data from a diverse range of IT researchers in semistructured interviews. This data is presented to show (1) the variation in meaning associated with the idea of significance and value and (2) the awareness structures through which participants experience significance and value. An Outcome Space represents the interrelation between those different ways of seeing, revealing a widening awareness. Five categories of ways of seeing the significance and value of research projects were found: The Personal Goals Conception, The Research Currency Conception, The Design of the Research Project Conception, The Outcomes for the Technology End User Conception and The Solving Real-World Problems Conception. These are situated within three wider perceptual boundaries: The Individual, The Research Community and Humankind. The categories are described in detail, demonstrated with participants’ quotes and illustrated with diagrams. A tentative comparison is made between this project and a similar investigation of IT professionals’ ways of seeing the significance and value of IT research projects. Finally, some recommendations for further research are made

The collective consciousness of Information Technology research: The significance and value of research projects. B. The views of IT industry professionals

This research seeks to reveal the different perceptual worlds in a research community, with the longterm intent of fostering increased understanding and hence collaboration. In the relatively new field of information technology (IT) research, available evidence suggests that a shared understanding of the research object or territory does not yet exist. This has led to the development of different perceptions amongst IT researchers of what constitutes significant and valuable research. Phenomenological methodology is used to elicit data from a diverse range of IT industry professionals in semi-structured interviews. This data is presented to show (1) the variation in meaning associated with the idea of significance and value and (2) the awareness structures through which participants experience significance and value. An Outcome Space represents the interrelation between those different ways of seeing, revealing a widening awareness. Five categories of ways of seeing the significance and value of research projects were found: The Personal Goals Conception, The Commercial Goals Conception, The Outcomes for the Technology End User Conception, The Solving Real-World Problems Conception and The Design of the Research Project Conception. These are situated within three wider perceptual boundaries: The Individual, The Enterprise and Society. The categories are described in detail, demonstrated with participants’ quotes and illustrated with diagrams. A tentative comparison is made between this project and a similar investigation of IT researchers’ ways of seeing the significance and value of IT research projects. Finally, some recommendations for further research are made

The Collective Consciousness of Information Technology Research: Ways of seeing Information Technology Research: Its Objects and Territories

The collective consciousness of effective groups of researchers is characterised by shared understandings of their research object or territory. In the relatively new field of information technology research, rapid expansion and fragmentation of the territory has led to different perceptions about what constitutes information technology research. This project explores a facet of the collective consciousness of disparate groups of researchers and lays a foundation for constructing shared research objects. Making IT researchers’ ways of seeing explicit may help us understand some of the complexities associated with inter and intra disciplinary collaboration amongst research groups, and the complexities associated with technology transfer to industry. This report analyses IT research, its objects and territories, as they are constituted by IT researchers associated with the sub-disciplines of information systems, computer science and information security. A phenomenographic approach is used to elicit data from a diverse range of IT researchers in semistructured interviews. This data is analysed to show (1) the variation in meaning associated with the idea of IT research and (2) the awareness structures through which participants experience variation in ways of seeing the object and territories of IT research. An Outcome Space represents the interrelation between different ways of seeing the territory. Eight ways of seeing IT research, its objects and territories, were found: The Technology Conception, The Information Conception, The Information and Technology Conception, The Communication Conception, The Ubiquitous Conception, The Sanctioned Conception, The Dialectic Conception and The Constructed Conception. These are described in detail and illustrated with participants’ quotes. Finally, some recommendations for further research are made

Trading on time

The authors determine how time delays affect international trade using newly collected World Bank data on the days it takes to move standard cargo from the factory gate to the ship in 126 countries. They estimate a modified gravity equation, controlling for endogeneity and remoteness. On average, each additional day that a product is delayed prior to being shipped reduces trade by at least 1 percent. Put differently, each day is equivalent to a country distancing itself from its trade partners by 70 kilometers on average. Delays have an even greater impact on developing country exports and exports of time-sensitive goods, such as perishable agricultural products. In particular, a day's delay reduces a country's relative exports of time-sensitive to time-insensitive agricultural goods by 6 percent.Free Trade,Economic Theory&Research,Trade Policy,Common Carriers Industry,Transport and Trade Logistics

An Efficient Data-aided Synchronization in L-DACS1 for Aeronautical Communications

L-band Digital Aeronautical Communication System type-1 (L-DACS1) is an emerging standard that aims at enhancing air traffic management (ATM) by transitioning the traditional analog aeronautical communication systems to the superior and highly efficient digital domain. L-DACS1 employs modern and efficient orthogonal frequency division multiplexing (OFDM) modulation technique to achieve more efficient and higher data rate in comparison to the existing aeronautical communication systems. However, the performance of OFDM systems is very sensitive to synchronization errors. L-DACS1 transmission is in the L-band aeronautical channels that suffer from large interference and large Doppler shifts, which makes the synchronization for L-DACS more challenging. This paper proposes a novel computationally efficient synchronization method for L-DACS1 systems that offers robust performance. Through simulation, the proposed method is shown to provide accurate symbol timing offset (STO) estimation as well as fractional carrier frequency offset (CFO) estimation in a range of aeronautical channels. In particular, it can yield excellent synchronization performance in the face of a large carrier frequency offset.Comment: In the proceeding of International Conference on Data Mining, Communications and Information Technology (DMCIT