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Showing papers by "Pompeu Fabra University published in 1999"


Journal ArticleDOI
TL;DR: In this paper, the authors developed and estimated a structural model of inflation that allows for a fraction of firms that use a backward-looking rule to set prices, and the model nests the purely forward-looking New Keynesian Phillips curve as a particular case.

2,514 citations


Journal ArticleDOI
TL;DR: In this article, the authors examine the relation between the innovation strategy and industry-, firm and innovation-specific characteristics using Belgian company data from the Eurostat Community Innovation Survey (CIS).

1,020 citations


Journal ArticleDOI
17 Sep 1999-Science
TL;DR: This study documents the direct interaction of a hormone with a voltage-gated channel subunit and provides the molecular mechanism for the modulation of vascular smooth muscle Maxi-K channels by estrogens.
Abstract: Maxi-K channels consist of a pore-forming alpha subunit and a regulatory beta subunit, which confers the channel with a higher Ca(2+) sensitivity. Estradiol bound to the beta subunit and activated the Maxi-K channel (hSlo) only when both alpha and beta subunits were present. This activation was independent of the generation of intracellular signals and could be triggered by estradiol conjugated to a membrane-impenetrable carrier protein. This study documents the direct interaction of a hormone with a voltage-gated channel subunit and provides the molecular mechanism for the modulation of vascular smooth muscle Maxi-K channels by estrogens.

493 citations


Journal ArticleDOI
TL;DR: It is shown how equity weights may serve to incorporate concerns for severity and potentials for health in QALY calculations and is suggested that for chronically ill or disabled people a life year gained should count as one and no less than one as long as the year is considered preferable to being dead by the person concerned.
Abstract: The paper addresses some limitations of the QALY approach and outlines a valuation procedure that may overcome these limitations. In particular, we focus on the following issues: the distinction between assessing individual utility and assessing societal value of health care; the need to incorporate concerns for severity of illness as an independent factor in a numerical model of societal valuations of health outcomes; similarly, the need to incorporate reluctance to discriminate against patients that happen to have lesser potentials for health than others; and finally, the need to combine measurements of health-related quality of life obtained from actual patients (or former patients) with measurements of distributive preferences in the general population when estimating societal value. We show how equity weights may serve to incorporate concerns for severity and potentials for health in QALY calculations. We also suggest that for chronically ill or disabled people a life year gained should count as one and no less than one as long as the year is considered preferable to being dead by the person concerned. We call our approach ‘cost-value analysis’. Copyright © 1999 John Wiley & Sons, Ltd.

388 citations


Posted Content
TL;DR: Research supported by the Spanish DGES grant PB96-0300, and USPHS grants DA00017 and DA01070.
Abstract: A family of scaling corrections aimed to improve the chi-square approximation of goodness-of-fit test statistics in small samples, large models, and nonnormal data was proposed in Satorra and Bentler (1994). For structural equations models, Satorra-Bentler's (SB) scaling corrections are available in standard computer software. Often, however, the interest is not on the overall fit of a model, but on a test of the restrictions that a null model say ${\cal M}_0$ implies on a less restricted one ${\cal M}_1$. If $T_0$ and $T_1$ denote the goodness-of-fit test statistics associated to ${\cal M}_0$ and ${\cal M}_1$, respectively, then typically the difference $T_d = T_0 - T_1$ is used as a chi-square test statistic with degrees of freedom equal to the difference on the number of independent parameters estimated under the models ${\cal M}_0$ and ${\cal M}_1$. As in the case of the goodness-of-fit test, it is of interest to scale the statistic $T_d$ in order to improve its chi-square approximation in realistic, i.e., nonasymptotic and nonnormal, applications. In a recent paper, Satorra (1999) shows that the difference between two Satorra- Bentler scaled test statistics for overall model fit does not yield the correct SB scaled difference test statistic. Satorra developed an expression that permits scaling the difference test statistic, but his formula has some practical limitations, since it requires heavy computations that are not available in standard computer software. The purpose of the present paper is to provide an easy way to compute the scaled difference chi-square statistic from the scaled goodness-of-fit test statistics of models ${\cal M}_0$ and ${\cal M}_1$. A Monte Carlo study is provided to illustrate the performance of the competing statistics.

369 citations


Journal ArticleDOI
TL;DR: In this paper, the enforcement of competition policy against collusion under leniency programs, which give reduced fines to firms revealing information to the Antitrust Authority, was studied, and the optimal policy under alternative rules and with homogeneous and heterogeneous cartels was analyzed.
Abstract: We study the enforcement of competition policy against collusion under Leniency Programs, which give reduced fines to firms revealing information to the Antitrust Authority. Such programs give firms an incentive to break collusion, but may also have a pro-collusive effect, since they decrease the expected cost of misbehaviour. We analyze the optimal policy under alternative rules and with homogeneous and heterogeneous cartels, obtaining a ranking of the different schemes and showing when the use of reduced fines may improve antitrust enforcement.

366 citations


Journal ArticleDOI
TL;DR: In this paper, an equilibrium search-matching model with risk-neutral agents and two-sided ex-ante heterogeneity was developed to address some political economy issues, and the model was used to address the differences in unemployment, productivity growth and wage inequality.
Abstract: We develop an equilibrium search-matching model with risk-neutral agents and two-sided ex-ante heterogeneity. Unemployment insurance has the standard effect of reducing employment, but also helps workers to get a suitable job. We show, through calibrations, how the mere difference on unemployment insurance, when countries experience a common skilled-biased technological shock, may result in differences in unemployment, productivity growth and wage inequality. These results are consistent with the contrasting performance of the labour market in Europe and the United States in the last twenty-five years. The model is used to address some political economy issues.

276 citations


Journal ArticleDOI
TL;DR: Results suggest that RP systems achieve better their postulated goals if cost inflation in pharmaceuticals is due to high prices rather than to the excess of prescription rates, and when the larger is the existing difference in prices among equivalent drugs, and more important is the actual market for generics.
Abstract: This paper reviews the literature on reference pricing (RP) in pharmaceutical markets. The RP strategy for cost containment of expenditure on drugs is analyzed as part of the procurement mechanism. We review the existing literature and the state-of-the-art regarding RP by focusing on its economic effects. In particular, we consider: (1) the institutional context and problem-related factors which appear to underline the need to implement an RP strategy, i.e., its nature, characteristics and the sort of health care problems commonly addressed; (2) how RP operates in practice, that is, how third party-payers (the insurers/buyers) have established the RP systems existing on the international scene (i.e., information methods, monitoring procedures and legislative provisions); (3) the range of effects resulting from particular RP strategies (including effects on choice of appropriate pharmaceuticals, insurer savings, total drug expenditures, prices of referenced and non-referenced products and dynamic efficiency; (4) the market failures which an RP policy is supposed to address and the main advantages and drawbacks which emerge from an analysis of its effects.

204 citations


Journal ArticleDOI
TL;DR: Impaired lung function occurring in patients with chronic obstructive pulmonary disease is associated with subcellular changes in their diaphragm, namely a shortening in the length of sarcomeres and an increase in the concentration of mitochondria, probably contributing to a better functional muscle behaviour.
Abstract: Pulmonary hyperinflation impairs the function of the diaphragm in patients with chronic obstructive pulmonary disease (COPD). However, it has been recently demonstrated that the muscle can counterbalance this deleterious effect, remodelling its structure (i.e. changing the proportion of different types of fibres). The aim of this study was to investigate whether the functional impairment present in COPD patients can be associated with structural subcellular changes of the diaphragm. Twenty individuals (60+/-9 yrs, 11 COPD patients and 9 subjects with normal spirometry) undergoing thoracotomy were included. Nutritional status and respiratory function were evaluated prior to surgery. Then, small samples of the costal diaphragm were obtained and processed for electron microscopy analysis. COPD patients showed a mean forced expiratory volume in one second (FEV1) of 60+/-9% predicted, a higher concentration of mitochondria (n(mit)) in their diaphragm than controls (0.62+/-0.16 versus 0.46+/-0.16 mitochondrial transections (mt) x microm(-2), p 37%) disclosed not only a higher n(mit) (0.63+/-0.17 versus 0.43+/-0.07 mt x microm(-2), p<0.05) but shorter sarcomeres (L(sar)) than subjects without this functional abnormality (2.08+/-0.16 to 2.27+/-0.15 microm, p<0.05). Glycogen stores were similar in COPD and controls. The severity of airways obstruction (i.e. FEV1) was associated with n(mit) (r=-0.555, p=0.01), while the amount of air trapping (i.e. RV/TLC) was found to correlate with both n(mit) (r=0.631, p=0.005) and L(sar) (r=-0.526, p<0.05). Finally, maximal inspiratory pressure (PI,max) inversely correlated with n(mit) (r=-0.547, p=0.01). In conclusion, impairment in lung function occurring in patients with chronic obstructive pulmonary disease is associated with subcellular changes in their diaphragm, namely a shortening in the length of sarcomeres and an increase in the concentration of mitochondria. These changes form a part of muscle remodelling, probably contributing to a better functional muscle behaviour.

204 citations


Journal ArticleDOI
TL;DR: In this article, the authors consider a two-stage game in which each player can either commit to a quantity in stage 1 or wait till stage 2, and they show that committing is more risky for the high cost firm and that, consequently, risk dominance considerations, as in Harsanyi and Selten (1988), allow the conclusion that only the low cost firm will choose to commit.

198 citations


Journal ArticleDOI
TL;DR: In this article, the authors estimate agglomeration-effects for France, Germany, Italy, Spain, and the UK, taking into account endogeneity of the spatial distribution of employment and spatial fixed-effects.
Abstract: The paper estimates agglomeration-effects for France, Germany, Italy, Spain, and the UK. Estimation takes into account endogeneity of the spatial distribution of employment and spatial fixed-effects. Empirical results suggest that agglomeration-effects in these European countries are only slightly smaller than agglomeration-effects in the US: the estimated elasticity of average-labor-productivity with respect to employment-density is 4.5 percent compared to 5 percent in the US.

Journal ArticleDOI
TL;DR: In this article, the authors report an experiment on the effect of intergroup competition on group coordination in the minimal-effort game (Van Huyck et al., 1990), where each player in each group independently chose an integer from 1 to 7.
Abstract: We report an experiment on the effect of intergroup competition on group coordination in the minimal-effort game (Van Huyck et al., 1990). The competition was between two 7-person groups. Each player in each group independently chose an integer from 1 to 7. The group with the higher minimum won the competition and each of its members was paid according to the game?s original payoff matrix. Members of the losing group were paid nothing. In case of a tie, each player was paid half the payoff in the original matrix. This treatment was contrasted with two control treatments where each of the two groups played an independent coordination game, either with or without information about the minimum chosen by the outgroup. Although the intergroup competition does not change the set of strict equilibria, we found that it improved collective rationality by moving group members in the direction of higher-payoff equilibria. Merely providing group members with information about the minimal-effort level in the other group was not sufficient to generate this effect.

Journal ArticleDOI
TL;DR: This paper examined the sensitivity of turning points classification to detrending and compared the implied cycles to those derived by NBER or DOC researchers, and found that turning point dates are broadly insensitive to detending with one dating rule but not the other and many procedures generate false alarms and miss several common turning points with the latter one.
Abstract: We examine the sensitivity of turning points classification to detrending and compare the implied cycles to those derived by NBER or DOC researchers. Two dating rules are considered. Turning point dates are broadly insensitive to detrending with one dating rule but not the other and many procedures generate false alarms and miss several common turning points with the latter one. Amplitude and duration properties are also sensitive detrending and dating rules. The Hodrick and Prescott and a frequency domain filters are best in mimicing NBER and DOC cycles, regardless of the dating rule used.

Posted Content
TL;DR: Kraay and Ventura as mentioned in this paper constructed a world equilibrium model in which productivity varies across countries and international borrowing and lending take place to exploit good investment opportunities, and generated the novel prediction that favorable income shocks lead to current account deficits in debtor countries and current account surpluses in creditor countries.
Abstract: What is the current account response to a transitory income shock? This model predicts that favorable income shocks lead to current account deficits in debtor countries and current account surpluses in creditor countries. Kraay and Ventura reexamine a classic question in international economics: What is the current account response to a transitory income shock such as a temporary improvement in the terms of trade, a transfer from abroad, or unusually high production? To answer this question, they construct a world equilibrium model in which productivity varies across countries and international borrowing and lending take place to exploit good investment opportunities. Despite its conventional ingredients, the model generates the novel prediction that favorable income shocks lead to current account deficits in debtor countries and current account surpluses in creditor countries. Evidence from thirteen OECD countries broadly supports this theoretical prediction. This paper - a product of the Macroeconomics and Growth Division, Development Research Group - is part of a larger effort in the group to study open-economy macroeconomics.

Journal ArticleDOI
TL;DR: In this paper, the authors examined the impact of the Colombian Labor Market Reform of 1990, which substantially reduced dismissal costs, on worker turnover by exploiting the temporal change in the Colombian labor legislation as well as the variability in coverage between formal and informal sector workers.
Abstract: Reductions in firing costs are often advocated as a way of increasing the dynamism of labor markets in both developed and less developed countries. Evidence from Europe and the U.S. on the impact of firing costs has, however, been mixed. Moreover, legislative changes both in Europe and the U.S. have been limited. This paper, instead, examines the impact of the Colombian Labor Market Reform of 1990, which substantially reduced dismissal costs. I estimate the incidence of a reduction in firing costs on worker turnover by exploiting the temporal change in the Colombian labor legislation as well as the variability in coverage between formal and informal sector workers. Using a grouping estimator to control for common aggregate shocks and selection, I find that the exit hazard rates into and out of unemployment increased after the reform by over 1 percent for formal workers (covered by the legislation) relative to informal workers (uncovered). The increase of the hazards implies a net decrease in unemployment of a third of a percentage point, which accounts for about one quarter of the fall in unemployment during the period of study.

Journal ArticleDOI
TL;DR: A dramatic reduction of the haplotype genetic diversity was observed in the villages at high altitude, especially in the highland Kirghiz, when compared with the village at low altitude, which suggests a male founder effect in the settlement of high-altitude lands.
Abstract: Summary Eight Y-linked short-tandem-repeat polymorphisms (DYS19, DYS388, DYS389I, DYS389II, DYS390, DYS391, DYS392, and DYS393) were analyzed in four populations of Central Asia, comprising two lowland samples—Uighurs and lowland Kirghiz—and two highland samples—namely, the Kazakhs (altitude 2,500 m above sea level) and highland Kirghiz (altitude 3,200 m above sea level). The results were compared with mtDNA sequence data on the same individuals, to study possible differences in male versus female genetic-variation patterns in these Central Asian populations. Analysis of molecular variance (AMOVA) showed a very high degree of genetic differentiation among the populations tested, in discordance with the results obtained with mtDNA sequences, which showed high homogeneity. Moreover, a dramatic reduction of the haplotype genetic diversity was observed in the villages at high altitude, especially in the highland Kirghiz, when compared with the villages at low altitude, which suggests a male founder effect in the settlement of high-altitude lands. Nonetheless, mtDNA genetic diversity in these highland populations is equivalent to that in the lowland populations. The present results suggest a very different migration pattern in males versus females, in an extended historical frame, with a higher migration rate for females.

Journal ArticleDOI
TL;DR: In this article, the authors estimate a tobacco consumption rational addiction model with panel data, using a double-hurdle specification after testing that the factors governing the consumption equation are not the same as those that govern the participation equation.

Journal ArticleDOI
TL;DR: In this article, the authors consider the optimal behavior of the Lender of Last Resort (LOLR) in its microeconomic role regarding individual financial institutions in distress and show that the optimal policy has to be conditional on the amount of uninsured debt issued by the defaulting bank.
Abstract: This paper addresses the issue of the optimal behaviour of the Lender of Last Resort (LOLR) in its microeconomic role regarding individual financial institutions in distress. It has been argued that the LOLR should not intervene at the microeconomic level and let any defaulting institution face the market discipline, as it will be confronted with the consequences of the risks it has taken. By considering a simple cost benefit analysis we show that this position may lack a sufficient foundation. We establish that, instead, uder reasonable assumptions, the optimal policy has to be conditional on the amount of uninsured debt issued by the defaulting bank. Yet in equilibrium, because the rescue policy is costly, the LOLR will not rescue all the banks that fulfill the uninsured debt requirement condition, but will follow a mixed strategy. This we interpret as the confirmation of the "creative ambiguity" principle, perfectly in line with the central bankers claim that it is efficient for them to have discretion in lending to individual institutions. Alternatively, in other cases, when the social cost of a bank's bankruptcy is too high, it is optimal for the LOLR to bail out the insititution, and this gives support to the "too big to fail" policy.

Journal ArticleDOI
TL;DR: In this article, the authors analyzed a class of endogenous growth models with physical and human capital and with three alt-ematives uses of time: unqualified leisure, work and education.
Abstract: In this paper we analyze a class of endogenous growth models with physical and human capital and with three altematives uses of time: unqualified leisure, work and education. In contrast to some other related models, we find that, even in the absence of technological extemalities, there could be multiple balanced paths. We provide a characterization of the qualitative behavior of consumption, leisure, work and education over those balanced paths, and study their transitional dynamics.

Journal ArticleDOI
TL;DR: Genetic variability appears to be much more structured by lineage than by population, and the deep structure of the genetic variation in old genealogical units (haplogroups) challenges a population-based perspective in the comprehension of human genome diversity.
Abstract: Eleven biallelic polymorphisms and seven short-tandem-repeat (STR) loci mapping on the nonrecombining portion of the human Y chromosome have been typed in men from northwestern Africa. Analysis of the biallelic markers, which represent probable unique events in human evolution, allowed us to characterize the stable backgrounds or haplogroups of Y chromosomes that prevail in this geographic region. Variation in the more rapidly mutating genetic markers (STRs) has been used both to estimate the time to the most recent common ancestor for STR variability within these stable backgrounds and to explore whether STR differentiation among haplogroups still retains information about their phylogeny. When analysis of molecular variance was used to study the apportionment of STR variation among both genetic backgrounds (i.e., those defined by haplogroups) and population backgrounds, we found STR variability to be clearly structured by haplogroups. More than 80% of the genetic variance was found among haplogroups, whereas only 3.72% of the genetic variation could be attributed to differences among populations-that is, genetic variability appears to be much more structured by lineage than by population. This was confirmed when two population samples from the Iberian Peninsula were added to the analysis. The deep structure of the genetic variation in old genealogical units (haplogroups) challenges a population-based perspective in the comprehension of human genome diversity. A population may be better understood as an association of lineages from a deep and population-independent gene genealogy, rather than as a complete evolutionary unit.

Journal ArticleDOI
TL;DR: In this article, the authors characterize a class of simple adaptive strategies, in the repeated play of a game, having the Hannanconsistency property: in the long run, the player is guaranteed an average payoff as large as the best-reply payoff to the empirical distribution of play of the other players; i.e., there is no "regret."
Abstract: We exhibit and characterize an entire class of simple adaptive strategies, in the repeated play of a game, having the Hannan-consistency property: In the long-run, the player is guaranteed an average payoff as large as the best-reply payoff to the empirical distribution of play of the other players; i.e., there is no "regret." Smooth fictitious play (Fudenberg and Levine [1995]) and regret-matching (Hart and Mas-Colell [1998]) are particular cases. The motivation and application of this work come from the study of procedures whose empirical distribution of play is, in the long-run, (almost) a correlated equilibrium. The basic tool for the analysis is a generalization of Blackwell's [1956a] approachability strategy for games with vector payoffs.

Posted Content
TL;DR: In this article, the authors model systemic risk in an interbank market and investigate the ability of the banking industry to withstand the insolvency of one bank and whether the closure of a bank generates a chain reaction on the rest of the system.
Abstract: We model systemic risk in an interbank market. Banks face liquidity needs as consumers are uncertain about where they need to consume. Interbank credit lines allow banks to cope with these liquidity shocks while reducing the cost of maintaining reserves. However, the interbank market exposes the system to a coordination failure (gridlock equilibrium) even if all banks are solvent. When one bank is insolvent, the stability of the banking system is affected in various ways depending on the patterns of payments across locations. We investigate the ability of the banking industry to withstand the insolvency of one bank and whether the closure of one bank generates a chain reaction on the rest of the system. We analyze the coordinating role of the Central Bank in preventing payments' systemic repercussions and we examine the justification of the "too-big-to-fail-policy".

Journal ArticleDOI
TL;DR: Two indices of deprivation strongly predict mortality in two age groups in Spain, and there is great potential for reducing mortality if the excess risk in more deprived areas fell to the level of the most affluent areas.
Abstract: STUDY OBJECTIVE: To analyse the geographical patterns and the magnitude of the association between deprivation and mortality in Spain. To estimate the excess of mortality in more deprived areas of the country by region. DESIGN: Cross sectional ecological study using 1991 census variables and mortality data for 1987-1992. SETTING: 2220 small areas in Spain. MAIN RESULTS: A geographical gradient from north east to south west was shown by both mortality and deprivation levels in Spain. Two dimensions of deprivation (that is, Index 1 and Index 2) obtained by exploratory factor analysis using four census indicators were found to predict mortality: mortality over 65 years of age was more associated with Index 1, while mortality under 65 years of age was more associated with Index 2. Excess mortality in the most deprived areas accounted for about 35,000 deaths. CONCLUSIONS: Two indices of deprivation strongly predict mortality in two age groups. Excess number of deaths in the most deprived geographical areas account for 10% of total number of deaths annually. In Spain there is great potential for reducing mortality if the excess risk in more deprived areas fell to the level of the most affluent areas.

Journal ArticleDOI
TL;DR: A formulation that locates hubs on a network in a competitive environment where customer capture is sought, which happens whenever the location of a new hub results in a reduction of the current cost of the traffic that goes from the specified origin to the specified destination.

Journal ArticleDOI
TL;DR: This article showed that the distribution and interpretation of degree modifiers is sensitive both to the scalar structure of the adjectives they modify and to the nature of the "standard values" according to which sentences involving adjectival predications are judged to be true.
Abstract: An issue of interest to work in areas ranging from lexical semantics to natural language processing (especially automatic text generation) to language pedagogy is the semantics of degree modification by expressions like very, well,and much Focusing on the case of deverbal gradable adjectives (such as acquainted), we show that/nthe selective behavior of different degree modifiers provides an important probe on the semantic typology of adjectives Specifically, we demonstrate that the distribution and interpretation of degree modifiers is sensitive both to the scalar structure of the adjectives they modify and to the nature of the “standard values” according to/nwhich sentences involving adjectival predications are judged to be true We further show that the scalar structure of deverbal gradable adjectives is determined by the aspectual properties of the source verbs, making it possible to accurately predict both which degree modifiers will be acceptable with which participles, and how/nthey will be interpreted

Journal ArticleDOI
TL;DR: In this paper, the Satorra-Bentler scaling corrections are used to improve the chi-square approximation of goodness-of-fit test statistics in small samples, large models, and nonnormal data.
Abstract: A family of scaling corrections aimed to improve the chi-square approximation of goodness-of-fit test statistics in small samples, large models, and nonnormal data was proposed in Satorra and Bentler (1994). For structural equations models, Satorra-Bentler's (SB) scaling corrections are available in standard computer software. Often, however, the interest is not on the overall fit of a model, but on a test of the restrictions that a null model say M0 implies on a less restricted one M1. If T0 and T1 denote the goodness-of-fit test statistics associated to M0 and M1, respectively, then typically the difference Td = T0 - T1 is used as a chi-square test statistic with degrees of freedom equal to the difference on the number of independent parameters estimated under the models M0 and M1. As in the case of the goodness-of-fit test, it is of interest to scale the statistic Td in order to improve its chi-square approximation in realistic, i.e., nonasymptotic and nonnormal, applications. In a recent paper, Satorra (1999) shows that the difference between two Satorra-Bentler scaled test statistics for overall model fit does not yield the correct SB scaled difference test statistic. Satorra developed an expression that permits scaling the difference test statistic, but his formula has some practical limitations, since it requires heavy computations that are not available in standard computer software. The purpose of the present paper is to provide an easy way to compute the scaled difference chi-square statistic from the scaled goodness-of-fit test statistics of models M0 and M1. A Monte Carlo study is provided to illustrate the performance of the competing statistics.

Book
01 Jan 1999
TL;DR: In this article, a new method is proposed for constructing confidence intervals in autoregressive models with linear time trend, which is more general than previous approaches in that it works for arbitrary parameter values, but also because the innovations are a martingale difference sequence rather than i.i.d.
Abstract: A new method is proposed for constructing confidence intervals in autoregressive models with linear time trend. Interest focuses on the sum of the autoregressive coefficients because this parameter provides a useful scalar measure of the long-run persistence properties of an economic time series. Since the type of the limiting distribution of the corresponding OLS estimator, as well as the rate of its convergence, depend in a discontinuous fashion upon whether the true parameter is less than one or equal to one (that is, trend-stationary case or unit root case), the construction of confidence intervals is notoriously difficult. The crux of our method is to recompute the OLS estimator on smaller blocks of the observed data, according to the general subsampling idea of Politis and Romano (1994a), although some extensions of the standard theory are needed. The method is more general than previous approaches in that it works for arbitrary parameter values, but also because it allows the innovations to be a martingale difference sequence rather than i.i.d. Some simulation studies examine the finite sample performance.

Journal ArticleDOI
TL;DR: The results strongly suggest that early agriculture wheat was cultivated at Tell Halula under much wetter conditions than are currently to be found in the area, and the presence of flax and its very high Δ values support this conclusion.
Abstract: The analysis of carbon isotope discrimination (Δ) in crop plant remains from archaeological sites may help to assess water availability for early agriculture. This study presents the analysis of Δ in seeds of naked wheat (Triticum aestivum/durum), lentil (Lens orientalis/culinaris), and flax (Linum sp.) found at the archaeological site of Tell Halula in the valley of the Middle Euphrates (Syria). This Neolithic site is the oldest in this region of the Fertile Crescent where the cultivation of domesticated plants has been reported, with seed remains ranging from 9550 to 8465 BP. Most of the seeds analysed showed Δ values greater than 16 ‰, reaching 20 ‰ for some samples of flax. For wheat, Δ values were much higher than those reported in present-day (1996) durum wheat crops cultivated under rainfed conditions in north-west Syria under environments with somewhat higher rainfall than Tell Halula. Similarly, grains of present-day (1997) barley cultivated in the archaeological site also showed lower values than those found in archaeological kernels. An empirical relationship between Δ of mature kernels and total precipitation (plus irrigation where applicable) from heading to maturity (r2 = 0.82, n = 11) was established for durum wheat, currently cultivated in different environments of the Mediterranean basin. The resulting relationship was applied to the data on Δ of wheat fossil kernels from Tell Halula to estimate the accumulated water inputs during the time (about 6 weeks) the kernels were produced. Calculated water inputs for wheat during early agriculture were (over 110 mm) at least 5 times higher than current-day rainfall accumulated in Tell Halula during the same phenological period. These results strongly suggest that early agriculture wheat was cultivated at Tell Halula under much wetter conditions than are currently to be found in the area. The presence of flax and its very high Δ values also support this conclusion. Whether such humid conditions during cultivation were due to moister conditions prevailing at this time, by planting in alluvial areas or by irrigation works is discussed.

Journal ArticleDOI
TL;DR: Members of the general public surveyed to see the relative importance of saving patients' lives when some patients could be returned to perfect health and others would live the remainder of their years with paraplegia found that all quality-adjusted life-years are created equal.
Abstract: Objectives: Decision-makers and the general public are often reluctant to adopt policy recommendations based exclusively upon cost–utility analyses One possible reason explored here is that patients' previous health state before experiencing the onset of an acute life-threatening illness may influence the value of saving those patients' lives Methods: We surveyed members of the general public to see the relative importance of saving patients' lives when some patients could be returned to perfect health and others would live the remainder of their years with paraplegia Among this latter group, some were described as having pre-existing paraplegia Others were described as having the onset of paraplegia The relative importance of saving each of these lives was measured using the person trade-off method Results: Six hundred five subjects completed questionnaires, and 250 met pre-established consistency criteria and were included in the final analysis Overall, subjects placed equal importance on saving the lives of people with pre-existing paraplegia versus those who could be returned to perfect health because they did not have pre-existing paraplegia In contrast, respondents gave lower priority to patients who would experience the onset of paraplegia after having their lives saved, especially if their paraplegia was avoidable with an alternative treatment Conclusion: People do not think that all quality-adjusted life-years are created equal Instead, the value that people place on treatment programs depends on patients' state of health before developing life-threatening illnesses, and on whether alternative treatments are available that provide better health outcomes for the patients These results may explain, in part, public discomfort over basing health care priorities on cost–utility analysis

Journal ArticleDOI
TL;DR: In this paper, the role played by fee income diversification and the enhancement, through disclosure rules, of market incentives to diversify, and the most efficient mix of services and corresponding quality safeguards.