17 research outputs found
The relationship between tax rates and tax revenues in eurozone member countries - exploring the Laffer curve
We estimate Laffer Curves for direct and indirect taxes for each Eurozone country, using panel data from 1995 to 2011, by means of Seemingly Unrelated Regression (SUR) models. We choose the three taxes that contribute the most to the government tax revenue: the value added tax (VAT), the corporate income tax (CT), and the labour income tax (LT). From our estimated significant parameters, which have the expected signs according to the Laffer Curve theory, we obtained a maximum/optimal tax rate for VAT for Greece, Portugal, and Slovakia and for the majority of the Eurozone countries for direct taxes. We also take into consideration the business cycle. Many countries do not present differences in regime, and when they do, the optimal tax rate is higher during recessions. Finally, we compare the observed tax rates in 2012 to the estimated optimal tax rates, to assess if the 2012 policy was located at the prohibitive range of the Laffer Curve. Our results are important for the discussions about fiscal discipline and harmonization in the Eurozone, since they exhibit important disparities between countries and taxes. We can see that, especially for CT and LT, there is a strong divide between the values of the optimal maximum tax rates for Eastern European countries and Western European economies. Additionally, the economic and financial conditions of each country also influence the value for the tax rate.info:eu-repo/semantics/acceptedVersio
Genetic relationships of brook lamprey of the genus Lampetra in a Pyrenean stream in Spain
The use of pit telemetry to study movements of ammocoetes and metamorphosing sea lampreys (Petromyzon marinus L.) in river beds.
Passive integrated transponder (PIT) tags were surgically implanted in 118 sea lamprey Petromyzon marinus ammocoetes which were left to recover in the laboratory for 2 months. During this period 55 individuals started to metamorphose. In the late summer of 2002 the tagged animals were released in a small tributary of the River Mondego, Portugal, and were regularly monitored for a period of 2 months using a portable PIT tag reader. The distribution of the released animals changed from an initial uniform pattern to a random distribution, and then to an aggregated pattern. At the end of the first week 60% of the tagged sea lampreys had already left the study area, indicating their dynamic behaviour. Ammocoetes were more active than metamorphosing sea lampreys, and downstream movements were more frequent when compared to the upstream ones, which were usually a short distance. In order to determine the influence of the dark-light cycle in the diel activity rhythms, 10 tagged sea lamprey ammocoetes were released in a tank (2000 l capacity) and their position monitored twice a day, for a period of 1 month. Ammocoetes locomotor activity appeared to be conditioned by circadian rhythms, and they were particularly active during darkness
Evolutionary history of lamprey paired species Lampetra fluviatilis (L.) and Lampetra planeri (Bloch) as inferred from mitochondrial DNA variation
A remarkable trend in the evolution of lampreys is the occurrence in most genera of ‘paired
species’, in which the parasitic anadromous lampreys are believed to have given rise to nonparasitic
freshwater resident populations. The present work examines the phylogeography
of the European paired species
Lampetra fluviatilis
and
Lampetra planeri
, in an attempt to
elucidate species pair evolutionary history. We studied sequence variation in cytochrome
b
and ATPase 6, 8 mitochondrial genes in 63 individuals from 21 localities of the paired
species throughout their distribution range. Results from the phylogenetic and nested
clade analyses were largely consistent, suggesting the existence of three major evolutionary
lineages: lineage I and possibly lineage II are widespread throughout Europe, while the
most ancestral lineage III is apparently restricted to the Iberian Peninsula. The high genetic
diversity observed in the Iberian Peninsula is probably the result of refugial persistence
and subsequent accumulation of variation over several ice ages, whereas the low levels of
genetic diversity observed in central and northern Europe should reflect a rapid postglacial
colonization. Results suggest that
L. planeri
originated within at least two distinct
evolutionary lineages, rejecting the single origin hypothesis. The observed lack of taxa
monophyly within lineage I may be the result of ongoing gene flow if the two taxa are
alternate life-history forms of a single species. However, structure within lineage I is also
consistent with the hypothesis of divergence of taxa after postglacial dispersion (around
2000 generations ago) with incomplete lineage sorting. Further testing of the alternative
hypotheses is warranted
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The use of PIT telemetry to study movements of ammocoetes and metamorphosing sea lampreys in river beds
Análise em fluxo aplicada à rotina de um laboratório de pesquisa agropecuária. desenvolvimento: Livro de resumo.
Genetic calibration of species diversity among North America's freshwater fishes
Freshwater ecosystems are being heavily exploited and degraded by human activities all over the world, including in North America, where fishes and fisheries are strongly affected. Despite centuries of taxonomic inquiry, problems inherent to species identification continue to hamper the conservation of North American freshwater fishes. Indeed, nearly 10% of species diversity is thought to remain undescribed. To provide an independent calibration of taxonomic uncertainty and to establish a more accessible molecular identification key for its application, we generated a standard reference library of mtDNA sequences (DNA barcodes) derived from expert-identified museum specimens for 752 North American freshwater fish species. This study demonstrates that 90% of known species can be delineated using barcodes. Moreover, it reveals numerous genetic discontinuities indicative of independently evolving lineages within described species, which points to the presence of morphologically cryptic diversity. From the 752 species analyzed, our survey flagged 138 named species that represent as many as 347 candidate species, which suggests a 28% increase in species diversity. In contrast, several species of parasitic and nonparasitic lampreys lack such discontinuity and may represent alternative life history strategies within single species. Therefore, it appears that the current North American freshwater fish taxonomy at the species level significantly conceals diversity in some groups, although artificially creating diversity in others. In addition to providing an easily accessible digital identification system, this study identifies 151 fish species for which taxonomic revision is required