Determinants of internal carbon pricing

Action against climate change is urgent and requires the participation of firms. The progressive internalization of carbon costs by firms is essential in the transition to a low-carbon economy. Internal carbon pricing is an emerging set of practices voluntarily adopted by companies to embed climate footprint in operations and business models. We explore the factors that explain the adoption of internal carbon prices (ICP) among global companies reporting to the Carbon Disclosure Project between 2015 and 2017. We specifically test whether the macroeconomic, regulatory, industry, and firm-specific characteristics affect the disclosed level of the ICPs. Results show that the ICPs depend to a large extent on the national climate policy, country's development, industry, and corporate governance. Furthermore, context explain more the differences in ICP than industry and firm-specific characteristics. Thus uncertainties around countries' climate policy hampers carbon pricing in business. These findings shed light on the factors that contribute to the dissemination of carbon pricing in society.info:eu-repo/semantics/acceptedVersio

Market-pull policies to promote renewable energy: a quantitative assessment of tendering implementation

Policymakers ideally select the support mechanism that better foments renewable energy production at the lowest cost to comply with international climate agreements. Currently, tendering is the fastest rising scheme. Yet a quantitative assessment of its performance in the literature is missing. We assess the effect of the introduction of auctions in accelerating the addition of renewable capacity through three econometric models: fixed-effects multivariate regression, statistical matching and synthetic control. The dataset includes 20 developed countries, spanning from 2004 to 2014, and both macroeconomic and policy drivers. Results show that tendering has the strongest effects to promote net renewable capacity comparing to other mechanisms like feed-in tariffs. Countries implementing tendering on average have a higher addition of net capacity of renewables in the order of 1000-2000 MW annually. The positive effect of tenders is clearer when analyzing with synthetic controls the case of Italy: while tendering enhances the deployment of renewables, policy instability jeopardizes the sustainability of tendering’s impact.info:eu-repo/semantics/acceptedVersio

Do crowdfunding returns reward risk? Evidences from clean-tech projects

The growing literature on crowdfunding has mostly focused on the determinants of campaigns success, as well as on the legal and macroeconomic drivers of the crowdfunding diffusion as a mean to finance innovative projects. Still there are scant evidences on whether the returns for crowdfunders are consistent with the risk profile of crowdfunded projects. By studying 365 European clean-tech projects which raised capital via crowdfunding, we show that once the country risk has been accounted for, the returns are not consistent with the risks related to the technology adopted by the projects. Behavioral factors like bounded rationality or the cultural dimension of investors may explain this apparent mispricing of risks. While projects' returns are, on average, negatively related to risks, we find that projects offering better risk-adjusted returns attract relatively larger average contributions. Our results have important implications for understanding the drivers of crowdfunding returns and its sustainability, and particularly for its diffusion as an instrument to foster the transition to a low-carbon economy.info:eu-repo/semantics/acceptedVersio

Interactions and scattering of quantum vortices in a polariton fluid

Quantum vortices, the quantized version of classical vortices, play a prominent role in superfluid and superconductor phase transitions. However, their exploration at a particle level in open quantum systems has gained considerable attention only recently. Here we study vortex pair interactions in a resonant polariton fluid created in a solid-state microcavity. By tracking the vortices on picosecond time scales, we reveal the role of nonlinearity, as well as of density and phase gradients, in driving their rotational dynamics. Such effects are also responsible for the split of composite spin-vortex molecules into elementary half-vortices, when seeding opposite vorticity between the two spinorial components. Remarkably, we also observe that vortices placed in close proximity experience a pull-push scenario leading to unusual scattering-like events that can be described by a tunable effective potential. Understanding vortex interactions can be useful in quantum hydrodynamics and in the development of vortex-based lattices, gyroscopes, and logic devices.Comment: 12 pages, 7 figures, Supplementary Material and 5 movies included in arXi

Pulse, polarization and topology shaping of polariton fluids

Here we present different approaches to ultrafast pulse and polarization shaping, based on a “quantum fluid” platform of polaritons. Indeed we exploit the normal modes of two dimensional polariton fluids made of strong coupled quantum well excitons and microcavity photons, by rooting different polarization and topological states into their sub-picosecond Rabi oscillations. Coherent control of two resonant excitation pulses allows us to prepare the desired state of the polariton, taking benefit from its four-component features given by the combination of the two normal modes with the two degrees of polarization. An ultrafast imaging based on the digital off-axis holography technique is implemented to study the polariton complex wavefunction with time and space resolution. We show in order coherent control of the polariton state on the Bloch sphere, an ultrafast polarization sweeping of the Poincaré sphere, and the dynamical twist of full Poincaré states such as the skyrmion on the sphere itself. Finally, we realize a new kind of ultrafast swirling vortices by adding the angular momentum degree of freedom to the two-pulse scheme. These oscillating topology states are characterized by one or more inner phase singularities tubes which spirals around the axis of propagation. The mechanism is devised in the splitting of the vortex into the upper and lower polaritons, resulting in an oscillatory exchange of energy and angular momentum and in the emitted time and space structured photonic packets

Interactions and scattering of quantum vortices in a polariton fluid

Quantum vortices, the quantized version of classical vortices, play a prominent role in superfluid and superconductor phase transitions. However, their exploration at a particle level in open quantum systems has gained considerable attention only recently. Here we study vortex pair interactions in a resonant polariton fluid created in a solid-state microcavity. By tracking the vortices on picosecond time scales, we reveal the role of nonlinearity, as well as of density and phase gradients, in driving their rotational dynamics. Such effects are also responsible for the split of composite spin–vortex molecules into elementary half-vortices, when seeding opposite vorticity between the two spinorial components. Remarkably, we also observe that vortices placed in close proximity experience a pull–push scenario leading to unusual scattering-like events that can be described by a tunable effective potential. Understanding vortex interactions can be useful in quantum hydrodynamics and in the development of vortex-based lattices, gyroscopes, and logic devices.MAT2016- 79866-R project (AEI/FEDER, UE)