The commodity terms of trade and their strategic implications for development

Although the empirical literature is not unanimous about the existence of a continuous long-term deterioration in the terms of trade for commodities (the original and most common formulation of the Prebisch- Singer hypothesis) and, hence, about the possibility of inferring their future behaviour on this basis, there is a consensus as to the sharp drop in the barter terms of trade, especially from the 1920s on. This paper presents a critical review of the theoretical and empirical literature on the subject and the implications for development strategies.Terms of trade, Economic development

The Dual Divergence: Growth Successes and Collapses in the Developing World since 1980

This paper argues that developing countries’ growth successes and collapses tend to cluster in specific time periods—and that only the existence of a global development cycle can explain this. The cycle reflects the external factors that affect all, or large clusters of developing countries, and thus constrain their growth possibilities. Nonetheless, country-specific factors—particularly patterns of specialization—play a significant role in determining growth dynamics. From this perspective, the paper shows a very large difference between the economic growth of developing countries diversifying into higher technology manufacturing exports and those experiencing success in natural resource intensive sectors.economic growth, divergence, external factors, global development cycle, patterns of specialization, technological intensity of exports

The terms of trade for commodities since the mid-19th century

This paper shows that there was an improvement in the barter terms of trade for non-fuel commodities vs. manufactures in the late 19th and early 20th centuries, followed by significant deterioration over the rest of the 20th century. However, the decline over most of the 20th century was neither continuous nor was it distributed evenly among different commodity groups. The far-reaching changes that the world economy underwent around 1920 and again around 1979 led to a stepwise deterioration which, over the long term, was reflected in roughly a halving of real commodity prices. Tropical agriculture fared the worst, whereas minerals had the best performance, with non-tropical agriculture in an intermediate situation. The increase experienced in the first decade of the 21st century may be the beginning of a long-term upward trend, but it is too soon to tell.Este ensayo muestra que hubo una mejoría en los términos de intercambio de trueque de los productos básicos a fines del siglo XIX y comienzos del XX, seguido por un deterioro significativo en el resto del siglo XX. Sin embargo, el deterioro durante la mayor parte del siglo XX no fue continuo ni se distribuyó en forma homogénea en diferentes grupos de productos. Los cambios de largo alcance que experimentó la economía mundial en torno a 1920 y nuevamente a 1979 se reflejaron en una caída escalonada, que a largo plazo redujo los precios reales de productos básicos aproximadamente a la mitad. La agricultura tropical experimento´ el peor desempeño y la minería el mejor, con la agricultura no tropical en una situación intermedia. El incremento de los precios que se experimento´ en la primera década del siglo XXI puede ser el inicio de una nueva fase de alza de larga duración, pero es demasiado temprano para saberlo

Entry Games under Private Information

We study market entry decisions when firms have private information about their profitability. We generalize current models by allowing general forms of market competition and heterogeneous firms that self-select when entering the market. Post-entry profits depend on market structure, and on the identities and the private information of the entering firms. We introduce a notion of the firm\u27s strength and show that an equilibrium where players\u27 strategies are ranked by strength, or herculean equilibrium, always exists. Moreover, when profits are elastic enough with respect to the firm\u27s private information, the herculean equilibrium is the unique equilibrium of the game

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Hypernode reduction modulo scheduling

Software pipelining is a loop scheduling technique that extracts parallelism from loops by overlapping the execution of several consecutive iterations. Most prior scheduling research has focused on achieving minimum execution time, without regarding register requirements. Most strategies tend to stretch operand lifetimes because they schedule some operations too early or too late. The paper presents a novel strategy that simultaneously schedules some operations late and other operations early, minimizing all the stretchable dependencies and therefore reducing the registers required by the loop. The key of this strategy is a pre-ordering that selects the order in which the operations will be scheduled. The results show that the method described in this paper performs better than other heuristic methods and almost as well as a linear programming method but requiring much less time to produce the schedules.Peer ReviewedPostprint (published version

Swing modulo scheduling: a lifetime-sensitive approach

This paper presents a novel software pipelining approach, which is called Swing Modulo Scheduling (SMS). It generates schedules that are near optimal in terms of initiation interval, register requirements and stage count. Swing Modulo Scheduling is an heuristic approach that has a low computational cost. The paper describes the technique and evaluates it for the Perfect Club benchmark suite. SMS is compared with other heuristic methods showing that it outperforms them in terms of the quality of the obtained schedules and compilation time. SMS is also compared with an integer linear programming approach that generates optimum schedules but with a huge computational cost, which makes it feasible only for very small loops. For a set of small loops, SMS obtained the optimum initiation interval in all the cases and its schedules required only 5% more registers and a 1% higher stage count than the optimumPeer ReviewedPostprint (published version

Modulo scheduling with reduced register pressure

Software pipelining is a scheduling technique that is used by some product compilers in order to expose more instruction level parallelism out of innermost loops. Module scheduling refers to a class of algorithms for software pipelining. Most previous research on module scheduling has focused on reducing the number of cycles between the initiation of consecutive iterations (which is termed II) but has not considered the effect of the register pressure of the produced schedules. The register pressure increases as the instruction level parallelism increases. When the register requirements of a schedule are higher than the available number of registers, the loop must be rescheduled perhaps with a higher II. Therefore, the register pressure has an important impact on the performance of a schedule. This paper presents a novel heuristic module scheduling strategy that tries to generate schedules with the lowest II, and, from all the possible schedules with such II, it tries to select that with the lowest register requirements. The proposed method has been implemented in an experimental compiler and has been tested for the Perfect Club benchmarks. The results show that the proposed method achieves an optimal II for at least 97.5 percent of the loops and its compilation time is comparable to a conventional top-down approach, whereas the register requirements are lower. In addition, the proposed method is compared with some other existing methods. The results indicate that the proposed method performs better than other heuristic methods and almost as well as linear programming methods, which obtain optimal solutions but are impractical for product compilers because their computing cost grows exponentially with the number of operations in the loop body.Peer ReviewedPostprint (published version

Types of Inheritance and Genes Associated with Familial Meniere Disease

Meniere disease (MD) is a rare disorder of the inner ear defined by sensorineural hearing loss (SNHL) associated with episodes of vertigo and tinnitus. The phenotype is variable, and it may be associated with other comorbidities such as migraine, respiratory allergies, and several autoimmune disorders. The condition has a significant heritability according to epidemiological and familial segregation studies. Familial MD is found in 10% of cases, the most frequently found genes being OTOG, MYO7A, and TECTA , previously associated with autosomal dominant and recessive non-syndromic SNHL. These findings suggest a new hypothesis where proteins involved in the extracellular structures in the apical surface of sensory epithelia (otolithic and tectorial membranes) and proteins in the stereocilia links would be key elements in the pathophysiology of MD. The ionic homeostasis of the otolithic and tectorial membranes could be critical to suppress the innate motility of individual hair cell bundles. Initially, focal detachment of these extracellular membranes may cause random depolarization of hair cells and will explain changes in tinnitus loudness or trigger vertigo attacks in early stages of MD. With the progression of the disease, a larger detachment will lead to an otolithic membrane herniation into the horizontal semicircular canal with dissociation in caloric and head impulse responses. Familial MD shows different types of inheritance, including autosomal dominant and compound recessive patterns and implementation of genetic testing will improve our understanding of the genetic structure of MD.CAUL and its Member InstitutionsAndalusian University, Research and Innovation Department (Grant# PREDOC2021/00343)Instituto de Salud Carlos III (Grant# PI20-1126)CIBERER (Grant# PIT21_GCV21),Andalusian University, Research and Innovation Department (PY20-00303, EPIMEN),Andalusian Health Department (Grant# PI027-2020), Asociacion Sindrome de Meniere España (ASMESMeniere’s Society, UK

Equilibrium Uniqueness in Entry Games with Private Information

We study equilibrium uniqueness in entry games with private information. Our framework embeds models commonly used in applied work, allowing rich forms of firm heterogeneity and selective entry. We introduce the notion of strength, which summarizes a firm’s ability to endure competition. In environments of applied interest, an equilibrium in which entry strategies are ranked according to strength, called herculean equilibrium, always exists. Thus, when the entry game has a unique equilibrium, it must be herculean. We derive simple sufficient conditions guaranteeing equilibrium uniqueness and, consequently, robust counterfactual analyses