IVA no comércio eletrónico : quais os obstáculos em sede de IVA dos bens adquiridos eletronicamente quando comparados com a aquisição por meios tradicionais?

A compra de bens através do comércio eletrónico é uma temática cada vez mais recorrente no quotidiano da população devido ao mundo cada vez mais digitalizado e globalizado em que vivemos. Com o aparecimento da Internet tornou-se essencial agir de forma proativa e tomar decisões quanto à tributação do comércio eletrónico, nomeadamente no que concerne ao imposto sobre o valor acrescentado (IVA). Desta forma e dada a relevância do tema exposto, surge este trabalho que tem como objetivo primordial dar resposta à questão de investigação “Quais os obstáculos em sede de IVA dos bens adquiridos eletronicamente quando comparados com a aquisição por meios tradicionais?” sendo que para tal irá ser realizada uma análise dos seguintes pontos: (i) identificar os obstáculos em sede de IVA enfrentados pelo comércio eletrónico indireto comparativamente com o comércio tradicional; (ii) indagar se as normas atuais estão ajustadas face às operações que se realizam eletronicamente, de forma a permitir transparência fiscal; e (iii) averiguar em que medida o negócio online coincide com o negócio tradicional, para se equacionar optar por um regime diferenciado. Pretendeu-se obter respostas a estas questões combinando metodologia quantitativa, através da seleção aleatória de sujeitos de investigação para responder a um questionário, com métodos qualitativos nomeadamente resultantes de dados recolhidos de entrevistas e documentos escritos. A investigação realizada envolveu 104 indivíduos enquanto consumidores finais e três empresas enquanto sujeitos passivos. Conclui-se que o comércio eletrónico de facto tem vindo a sentir uma evolução crescente e acentuada nos últimos anos. Relativamente ao comércio offline não foram encontrados entraves significativos que limitassem a sua opção em sede de IVA. Já no comércio online, existem dificuldades de aplicação da legislação, justificando-se que se proceda a reformulações no regime para acompanhar o avanço tecnológico.The purchase of goods through e-commerce is an increasingly recurrent subject in the daily lives of the population due to the increasingly digitized and globalized world we live in. With the emergence of this new reality of the Internet, it has become essential to proactively take decisions regarding the e-commerce taxation, namely about value added tax. For this reason and given the relevance of the subject, the main objective of this project is to answer the research question "What are the obstacles of buying goods through e-commerce, in the scope of VAT, comparing to the acquisition by traditional means?”. To answer this question an analysis of the following points will be carried out: (i) identifying the VAT obstacles faced by e-commerce offline in comparison with traditional trade; (ii) analyze whether the current legislation is adapted to e-commerce, in order to allow fiscal transparency; and (iii) to find out to what extent the online business coincides with the traditional business, in order to consider an alternative tax regime. In order to reach all these answers a quantitative methodology was used, through the random selection of individuals to answer a questionnaire, as well as qualitative methods, namely through data collected from interviews and written documents. The investigation involved 104 individuals as final consumers and three companies acting as taxable persons. It was concluded, that in fact e-commerce had suffered a major increase in recent years. Regarding the offline trading no significant barriers were found that limited its option, in the scope of VAT. On the other hand, the online commerce faces a complex tax legislation which means that updates are needed in order to keep up with the improvement and innovation of technologies

Combined fit to the spectrum and composition data measured by the Pierre Auger Observatory including magnetic horizon effects

The measurements by the Pierre Auger Observatory of the energy spectrum and mass composition of cosmic rays can be interpreted assuming the presence of two extragalactic source populations, one dominating the flux at energies above a few EeV and the other below. To fit the data ignoring magnetic field effects, the high-energy population needs to accelerate a mixture of nuclei with very hard spectra, at odds with the approximate E$^{-2}$ shape expected from diffusive shock acceleration. The presence of turbulent extragalactic magnetic fields in the region between the closest sources and the Earth can significantly modify the observed CR spectrum with respect to that emitted by the sources, reducing the flux of low-rigidity particles that reach the Earth. We here take into account this magnetic horizon effect in the combined fit of the spectrum and shower depth distributions, exploring the possibility that a spectrum for the high-energy population sources with a shape closer to E$^{-2}$ be able to explain the observations

Studies of the mass composition of cosmic rays and proton-proton interaction cross-sections at ultra-high energies with the Pierre Auger Observatory

In this work, we present an estimate of the cosmic-ray mass composition from the distributions of the depth of the shower maximum (Xmax) measured by the fluorescence detector of the Pierre Auger Observatory. We discuss the sensitivity of the mass composition measurements to the uncertainties in the properties of the hadronic interactions, particularly in the predictions of the particle interaction cross-sections. For this purpose, we adjust the fractions of cosmic-ray mass groups to fit the data with Xmax distributions from air shower simulations. We modify the proton-proton cross-sections at ultra-high energies, and the corresponding air shower simulations with rescaled nucleus-air cross-sections are obtained via Glauber theory. We compare the energy-dependent composition of ultra-high-energy cosmic rays obtained for the different extrapolations of the proton-proton cross-sections from low-energy accelerator data

Study of downward Terrestrial Gamma-ray Flashes with the surface detector of the Pierre Auger Observatory

The surface detector (SD) of the Pierre Auger Observatory, consisting of 1660 water-Cherenkov detectors (WCDs), covers 3000 km2 in the Argentinian pampa. Thanks to the high efficiency of WCDs in detecting gamma rays, it represents a unique instrument for studying downward Terrestrial Gamma-ray Flashes (TGFs) over a large area. Peculiar events, likely related to downward TGFs, were detected at the Auger Observatory. Their experimental signature and time evolution are very different from those of a shower produced by an ultrahigh-energy cosmic ray. They happen in coincidence with low thunderclouds and lightning, and their large deposited energy at the ground is compatible with that of a standard downward TGF with the source a few kilometers above the ground. A new trigger algorithm to increase the TGF-like event statistics was installed in the whole array. The study of the performance of the new trigger system during the lightning season is ongoing and will provide a handle to develop improved algorithms to implement in the Auger upgraded electronic boards. The available data sample, even if small, can give important clues about the TGF production models, in particular, the shape of WCD signals. Moreover, the SD allows us to observe more than one point in the TGF beam, providing information on the emission angle

Radio Interferometry applied to air showers recorded by the Auger Engineering Radio Array

A new radio interferometric technique was recently developed that takes into account time lags caused by the three-dimensional dependency of the refractive index in the atmosphere. It enables us to track the extensive air shower while it propagates through the atmosphere. Using this technique, properties of the air shower can be estimated, like the depth of maximum and the axis of propagation. In order to apply this method, strict constraints on the time-synchronisation between radio antennas in an array must be satisfied. In this contribution, we show that the Auger Engineering Radio Array can meet these timing criteria by operating a time reference beacon. We will show how this enables us to reconstruct air shower properties using the radio interferometric technique