Public debt sustainability. An empirical study on OECD countries

For a panel of 21 OECD heterogeneous countries from 1991 to 2015, we study governments’ reactions to the accumulation of debt and look at whether governments voluntary take corrective measures when the debt-GDP ratio starts rising or they rather let the debt grow. We distinguish between discretionary and automatic response of primary balance of government actions, as captured by the structural component of public primary balance and by cyclical component of public primary balance. We show the existence of a systematic long-term relationship between debt and structural primary balance supporting the view that the long-term governments’ discretionary response to increases in the debt-GDP ratio is negative, that is, governments are not currently taking long-term actions that counteract the increases in debts and do not satisfy the intertemporal budget constraint. In the short term, an asymmetric fiscal policy response exploiting the output gap, by part of the political class of the countries considered, seems to emerge: it intervenes with a new deficit and debt when the output gap is positive, but it does not adopt a symmetrical correction when the situation is reversed

Few-cycle Surface Plasmon Polariton Generation by Rotating Wavefront Pulses

A concept for the efficient generation of surface plasmon polaritons (SPPs) with a duration of very few cycles is presented. The scheme is based on grating coupling and laser pulses with wavefront rotation (WFR), so that the resonance condition for SPP excitation is satisfied only for a time window shorter than the driving pulse. The feasibility and robustness of the technique is investigated by means of simulations with realistic parameters. In optimal conditions, we find that a $29.5$~fs pulse with $800$~nm wavelength can excite a $3.8$~fs SPP ($\sim 1.4$ laser cycles) with a peak field amplitude $2.7$ times the peak value for the laser pulse

Laser-Driven Rayleigh-Taylor Instability: Plasmonics Effects and Three-Dimensional Structures

The acceleration of dense targets driven by the radiation pressure of high-intensity lasers leads to a Rayleigh-Taylor instability (RTI) with rippling of the interaction surface. Using a simple model it is shown that the self-consistent modulation of the radiation pressure caused by a sinusoidal rippling affects substantially the wavevector spectrum of the RTI depending on the laser polarization. The plasmonic enhancement of the local field when the rippling period is close to a laser wavelength sets the dominant RTI scale. The nonlinear evolution is investigated by three dimensional simulations, which show the formation of stable structures with "wallpaper" symmetry.Comment: 5 pages, 5 figures. New version includes 2D and 3D simulations. More details in the analytical calculation are given in the previous versio

Opportunism and MPs’ chances of re-election: an analysis of political transformism in the Italian parliament

We identify as political transformists the Italian members of parliament (MPs) who cross the aisle and vote for legislation opposed by their own political group—i.e., MPs who transform from the political opposition to the ruling parties (or from government supporters) into a force supporting the government (or opposition)—thus representing sources of party and governmental instability. Transformism, which characterized 471 MPs over the period considered, does not coincide with the broader phenomena of party switching already studied in political science. Once we disentangle the distinct behaviors, we study whether transformism helps extend the tenures of all 7128 MPs observed from 1946 to 2013. To the best of our knowledge, ours is the first work to consider the role of transformism in the survival of politicians. Our results suggest that transforming MPs suffer marked reductions in their survival probabilities, especially when compared with their fellow parliamentarians. However, transformist MPs, immediately after coming out as such, are more likely to survive than MPs remaining reliably loyal to their parties. That is, over time, transformists are punished by the electorate, but newly transformed politicians enjoy short-term comparative electoral advantages, thus shedding light on the relevance of a long-standing Italian political phenomenon

Seat belt use among rear passengers: validity of self-reported versus observational measures

<p>Abstract</p> <p>Background</p> <p>The effects of seat belt laws and public education campaigns on seat belt use are assessed on the basis of observational or self-reported data on seat belt use.</p> <p>Previous studies focusing on front seat occupants have shown that self-reports indicate a greater seat belt usage than observational findings.</p> <p>Whether this over-reporting in self reports applies to rear seat belt usage, and to what extent, have yet to be investigated.</p> <p>We aimed to evaluate the over-reporting factor for rear seat passengers and whether this varies by gender and under different compulsory seat belt use conditions.</p> <p>Methods</p> <p>The study was conducted in the Veneto Region, an area in the North-East of Italy with a population of 4.7 million.</p> <p>The prevalence of seat belt use among rear seat passengers was determined by means of a cross-sectional self-report survey and an observational study.</p> <p>Both investigations were performed in two time periods: in 2003, when rear seat belt use was not enforced by primary legislation, and in 2005, after rear seat belt use had become compulsory (June 2003).</p> <p>Overall, 8138 observations and 7902 interviews were recorded.</p> <p>Gender differences in the prevalence of rear seat belt use were examined using the chi-square test. The over-reporting factor, defined as the ratio of the self-reported to the observed prevalence of rear seat belt use, was calculated by gender before and after the rear seat belt legislation came into effect.</p> <p>Results</p> <p>Among rear seat passengers, self-reported rates were always higher than the observational findings, with an overall over-reporting factor of 1.4.</p> <p>We registered no statistically significant changes over time in the over-reporting factor, nor any major differences between genders.</p> <p>Conclusion</p> <p>Self-reported seat belt usage by rear passengers represents an efficient alternative to observational studies for tracking changes in actual behavior, although the reported figures need to be adjusted using an appropriate over-reporting factor in order to gain an idea of genuine seat belt use.</p

Suicide Mortality among Psychiatric Patients in Northeast Italy. A 10-year Cohort Study

Aims The present study investigated the relationship between suicide mortality and contact with a community mental health centre (CMHC) among the adult population in the Veneto Region (northeast Italy, population 4.9 million). Specifically, it estimated the effects of age, gender, time elapsed since the first contact with a CMHC, calendar year of diagnosis and diagnostic category on suicide mortality and modality. Methods The regional mortality archive was linked to electronic medical records for all residents aged 18–84 years who had been admitted to a CMHC in the Veneto Region in 2008. In total, 54 350 subjects diagnosed with a mental disorder were included in the cohortand followed up for a period of 10 years, ending in 2018. Years of life lost (YLL) were computed and suicide mortality was estimated as a mortality rate ratio (MRR). Results During the follow-up period, 4.4% of all registered deaths were from suicide, but, given the premature age of death (mean 52.2 years), suicide death accounted for 8.7% of YLL; this percentage was particularly high among patients with borderline personality disorder (27.2%), substance use disorder (12.1%) and bipolar disorder (11.5%) who also presented the highest suicide mortality rates. Suicide mortality rates were halved in female patients (MRR 0.45; 95% CI 0.37–0.55), highest in patients aged 45–54 years (MRR 1.56; 95% CI 1.09–2.23), and particularly elevated in the 2 months following first contact with CMHCs (MRR 10.4; 95% CI 5.30–20.3). A sensitivity analysis restricted to patients first diagnosed in 2008 confirmed the results. The most common modalities of suicide were hanging (47%), jumping (18%), poisoning (13%) and drowning (10%), whereas suicide from firearm was rare (4%). Gender, age at death and time since first contact with CMHCs influenced suicide modality. Conclusions Suicide prevention strategies must be promptly initiated after patients’ first contact with CMHCs. Patients diagnosed with borderline personality disorder, substance use disorder and bipolar disorder may be at particularly high risk for suicide

Suicide mortality among psychiatric patients in Northeast Italy: a 10-year cohort study

Aims: The present study investigated the relationship between suicide mortality and contact with a community mental health centre (CMHC) among the adult population in the Veneto Region (northeast Italy, population 4.9 million). Specifically, it estimated the effects of age, gender, time elapsed since the first contact with a CMHC, calendar year of diagnosis and diagnostic category on suicide mortality and modality. Methods: The regional mortality archive was linked to electronic medical records for all residents aged 18-84 years who had been admitted to a CMHC in the Veneto Region in 2008. In total, 54 350 subjects diagnosed with a mental disorder were included in the cohort and followed up for a period of 10 years, ending in 2018. Years of life lost (YLL) were computed and suicide mortality was estimated as a mortality rate ratio (MRR). Results: During the follow-up period, 4.4% of all registered deaths were from suicide, but, given the premature age of death (mean 52.2 years), suicide death accounted for 8.7% of YLL; this percentage was particularly high among patients with borderline personality disorder (27.2%), substance use disorder (12.1%) and bipolar disorder (11.5%) who also presented the highest suicide mortality rates. Suicide mortality rates were halved in female patients (MRR 0.45; 95% CI 0.37-0.55), highest in patients aged 45-54 years (MRR 1.56; 95% CI 1.09-2.23), and particularly elevated in the 2 months following first contact with CMHCs (MRR 10.4; 95% CI 5.30-20.3). A sensitivity analysis restricted to patients first diagnosed in 2008 confirmed the results. The most common modalities of suicide were hanging (47%), jumping (18%), poisoning (13%) and drowning (10%), whereas suicide from firearm was rare (4%). Gender, age at death and time since first contact with CMHCs influenced suicide modality. Conclusions: Suicide prevention strategies must be promptly initiated after patients' first contact with CMHCs. Patients diagnosed with borderline personality disorder, substance use disorder and bipolar disorder may be at particularly high risk for suicide