A new all-round density functional based on spin states and SN2 barriers

We report here a new empirical density functional that is constructed based on the performance of OPBE and PBE for spin states and SN 2 reaction barriers and how these are affected by different regions of the reduced gradient expansion. In a previous study [Swart, Sol̀, and Bickelhaupt, J. Comput. Methods Sci. Eng. 9, 69 (2009)] we already reported how, by switching between OPBE and PBE, one could obtain both the good performance of OPBE for spin states and reaction barriers and that of PBE for weak interactions within one and the same (SSB-sw) functional. Here we fine tuned this functional and include a portion of the KT functional and Grimme's dispersion correction to account for π- π stacking. Our new SSB-D functional is found to be a clear improvement and functions very well for biological applications (hydrogen bonding, π -π stacking, spin-state splittings, accuracy of geometries, reaction barriers)

Comparison of splice sites in mammals and chicken

We have carried out an initial analysis of the dynamics of the recent evolution of the splice-sites sequences on a large collection of human, rodent (mouse and rat), and chicken introns. Our results indicate that the sequences of splice sites are largely homogeneous within tetrapoda. We have also found that orthologous splice signals between human and rodents and within rodents are more conserved than unrelated splice sites, but the additional conservation can be explained mostly by background intron conservation. In contrast, additional conservation over background is detectable in orthologous mammalian and chicken splice sites. Our results also indicate that the U2 and U12 intron classes seem to have evolved independently since the split of mammals and birds; we have not been able to find a convincing case of interconversion between these two classes in our collections of orthologous introns. Similarly, we have not found a single case of switching between AT-AC and GT-AG subtypes within U12 introns, suggesting that this event has been a rare occurrence in recent evolutionary times. Switching between GT-AG and the noncanonical GC-AG U2 subtypes, on the contrary, does not appear to be unusual; in particular, T to C mutations appear to be relatively well tolerated in GT-AG introns with very strong donor sites.

Transcription, tagging and coding of bilingual corpora via LIDES

L'objectiu d'aquest informe és presentar l'aplicació d'una sèrie de propostes sobre transcripció, etiquetatge i codificació a dos corpus: el corpus bilingüe LC (La Canonja (Català-Espanyol)) i el corpus trilingüe CSCD (Code-switching as Communicative Design (Català-Espanyol-Anglès)). Aquestes propostes, que constitueixen l'aportació de l'equip IULA-LIPPS (Language Interaction in Plurilingual and Plurilectal Speakers) al manual de codificació del sistema LIDES (Language Interaction Database Exchange System), adoptat pel grup europeu LIPPS, poden ser útils per transcriure, etiquetar i codificar dades provinents de llengües tipològicament properes i distants.

Organizational Choice and Environmental Change

We explain the choice between franchising and vertical integration by estimating a model of relative performance in a sample of 250 Spanish car distributors, controlling for self-selection and including environmental factors. The method allows us to estimate performance counterfactuals. Organizational choice seemingly aims to contain moral hazard for both distributors and manufacturers but it is subject to start-up constraints and switching costs. While the market for franchises remained underdeveloped, information asymmetries led to the opening of integrated outlets. Their subsequent conversion into franchised outlets probably involved prohibitive transaction costs. Consequently, they performed worse than would have been expected had they been independent, as confirmed by the systematic improvement observed when they were in fact converted. The timing of such conversions suggests that switching costs were prohibitive until firms developed a substantial cushion of temporary contracts, previously forbidden by regulation.

Bands width, credibility and exchange risk: Lessons from the EMS experience

This paper presents an analysis of the credibility of the EMScurrencies that covers the period before and after the increase in thebands of fluctuation. Our credibility indicator is based on the inferredprobabilities derived from the estimation of a Markov-switching model(Hamilton (1989)) applied to the expected rate of depreciation. Theresults show that, for most of the currencies, credibility has improved,at least transitorily, after the increase in the bands. However, for allcurrencies, the credibility measured by the indicator proposed in thispaper has been eroded recently even with the widened bands.

The wage effect of an indexation clause: Evidence from Spanish manufacturing firms

An endogenous switching model of ex-ante wage changes under indexed and non-indexed settlements is estimated for the Spanish manufacturing sector using collective bargaining firm data for the 1984-1991 period. The likelihood of indexing the settlement is higher for nationwide unions than for other union groups within the works council and increases with the expected level of inflation. For wage change equations, a common structure for indexed and non-indexed settlements is strongly rejected, showing a source of nominal rigidity. For indexed contracts, the expected ex-ante total inflation coverage is nearly complete. It is also shown that workers pay a significant ex-ante wage change premium (differential) to obtain a cost of living allowance clause. However, the realised contingent compensation exceeds such a premium for all industries. Finally, important spillover effects in wage setting and the decision to index the settlement have been detected.

The impact of the reference price system on the pharmaceutical market: A theoretical approach

This article analyses the impact of the reference pricesystem on the price-setting strategies of thepharmaceutical firms and on the level of generic usage.This model is the first to take explicitly into accountthe impact of the reference price mechanism on the levelof competition between brand-name and generic drugs andnational pharmaceutical spending. We consider aduopolistic model with one firm producing the brand-namedrug, whose patent has already expired, and the otherproducing the corresponding generic version. We work ina partial equilibrium framework where firms set pricessequentially and consumers face heterogeneous switchingcosts.We show that brand producers compensate thedecline of profits by selling greater quantities insteadof charging higher prices, thus fostering pricecompetition in the pharmaceutical market. This result isa consequence of both the assumption of a verticallydifferentiated model and the introduction of thereference price system.

Negativity effect and the emergence of ideologies

``Negativity effect'' refers to the psychological phenomenon that peopletend to attach greater weight to negative information than to equallyextreme and equally likely positive information in a variety of informationprocessing tasks. Numerous studies of impression formation have found thatnegative information is weighted more heavily than positive information asimpressions of others are formed. There is empirical evidence in politicalscience that shows the importance of the negativity effect in the informationprocessing of the voters. This effect can explain the observed decreaseof popularity for a president the longer he is in office. \\We construct a dynamic model of political competition, incorporating thenegativity effect in the decision rule of the voters and allowing their preferencesto change over time, according to the past performance of the candidateswhile in office. Our model may explain the emergence of ideologies out ofthe competition for votes of myopic candidates freely choosing policypositions. This result gives rise to the formation of political parties,as infinitely--lived agents with a certain ideology. Furthermore, in thismodel some voters may start out by switching among parties associated withdifferent policies, but find themselves supporting one of the parties fromsome point on. Thus, the model describes a process by which some votersbecome identified with a ``right'' or ``left'' bloc, while others ``swing''between the two parties.

Temporary help agencies and workers' occupational mobility

This paper focuses on the occupational mobility of temporary helpagency workers by studying their job-to-job upgrading chances as opposedto those who have not been hired through these intermediaries. A screeningapproach to the role of those labor brokers suggests that agency workersmay expect greater chances of upgrading from one occupation to another.Results obtained with a sample of Spanish workers show that workingthrough those intermediaries comparatively offers stronger prospects ofoccupational upgrading for workers of a medium qualification level. Thisbasic result is reinforced when the existence of self-selection into thistype of intermediated work is appropriately taken into account.

The optimal length of contracts with application to outsourcing

This paper resolves three empirical puzzles in outsourcing by formalizing the adaptationcost of long-term performance contracts. Side-trading with a new partner alongside a long-term contract (to exploit an adaptation-requiring investment) is usually less effective than switching to the new partner when the contract expires. So long-term contracts that prevent holdup of specific investments may induce holdup of adaptation investments. Contract length therefore trades of specific and adaptation investments. Length should increase with the importance and specificity of self-investments, and decrease with the importance of adaptation investments for which side-trading is ineffective. My general model also shows how optimal length falls with cross-investments and wasteful investments.

Hybrid consumption paths in the attribute space: A model and application with scanner data

This paper presents and estimates a dynamic choice model in the attribute space considering rational consumers. In light of the evidence of several state-dependence patterns, the standard attribute-based model is extended by considering a general utility function where pure inertia and pure variety-seeking behaviors can be explained in the model as particular linear cases. The dynamics of the model are fully characterized by standard dynamic programming techniques. The model presents a stationary consumption pattern that can be inertial, where the consumer only buys one product, or a variety-seeking one, where the consumer shifts among varied products.We run some simulations to analyze the consumption paths out of the steady state. Underthe hybrid utility assumption, the consumer behaves inertially among the unfamiliar brandsfor several periods, eventually switching to a variety-seeking behavior when the stationary levels are approached. An empirical analysis is run using scanner databases for three different product categories: fabric softener, saltine cracker, and catsup. Non-linear specifications provide the best fit of the data, as hybrid functional forms are found in all the product categories for most attributes and segments. These results reveal the statistical superiority of the non-linear structure and confirm the gradual trend to seek variety as the level of familiarity with the purchased items increases.

Drivers and sources of supply flexibility: An exploratory study

Purpose - There has been much research on manufacturing flexibility, but supply chain flexibility is still an under-investigated area. This paper focuses on supply flexibility, the aspects of flexibility related to the upstream supply chain. Our purpose is to investigate why and how firms increase supply flexibility.Methodology/Approach An exploratory multiple case study was conducted. We analyzed seven Spanish manufacturers from different sectors (automotive, apparel, electronics and electrical equipment).Findings - The results show that there are some major reasons why firms need supply flexibility (manufacturing schedule fluctuations, JIT purchasing, manufacturing slack capacity, low level of parts commonality, demand volatility, demand seasonality and forecast accuracy), and that companies increase this type of flexibility by implementing two main strategies: to increase suppliers responsiveness capability and flexible sourcing . The results also suggest that the supply flexibility strategy selected depends on two factors: the supplier searching and switching costs and the type of uncertainty (mix, volume or delivery).Research limitations - This paper has some limitations common to all case studies, such as the subjectivity of the analysis, and the questionable generalizability of results (since the sample of firms is not statistically significant).Implications - Our study contributes to the existing literature by empirically investigating which are the main reasons for companies needing to increase supply flexibility, how they increase this flexibility, and suggesting some factors that could influence the selection of a particular supply flexibility strategy.

Money and prices in models of bounded rationality in high inflation economies

This paper studies the short run correlation of inflation and money growth. We study whether a model of learning can do better than a model of rational expectations, we focus our study on countries of high inflation. We take the money process as an exogenous variable, estimated from the data through a switching regime process. We findthat the rational expectations model and the model of learning both offer very good explanations for the joint behavior of money and prices.

How competition controls team production: The case of fishing firms

Under team production, those who monitor individual productivity areusually the only ones compensated with a residual that varies withthe performance of the team. This pattern is efficient, as is shownby the prevalence of conventional firms, except for small teams andwhen specialized monitoring is ineffective. Profit sharing in repeatedteam production induces all team members to take disciplinary actionagainst underperformers through switching and separation decisions,however. Such action provides effective self-enforcemnt when themarkets for team members are competitive, even for large teams usingspecialized monitoring. The traditional share system of fishing firmsshows that for this competition to provide powerful enough incentivesthe costs of switching teams and measuring team productivity must bebellow. Risk allocation may constrain the organizational designdefined by the use of a share system. It does not account for itsexistence, however.

How different are returns to education? Evidence from German school choices

This study presents estimates of returns to post-secondary educationand wage differentials among graduates fromdifferent secondary schoolsin Germany. I use an empirical model that captures the basic features ofthe German education system. It controls for selection into post-secondaryeducation and treats latter as endogenous in the wage equation. Myresults show that OLS estimates are severely biased. The direction ofthe bias depends on the secondary school type. Annual returns topost-secondary education differ significantly: they are eight timeshigher for graduates from the highest secondary school than for graduatesfrom the lowest secondary school.