Archivio istituzionale della Ricerca - Bocconi
Not a member yet
30225 research outputs found
Sort by
Concentration of discrepancy-based approximate Bayesian computation via Rademacher complexity
No full textThere has been an increasing interest on summary-free solutions for approximate Bayesian computation (ABC) that replace distances among summaries with discrepancies between the empirical distributions of the observed data and the synthetic samples generated under the proposed parameter values. The success of these strategies has motivated theoretical studies on the limiting properties of the induced posteriors. However, there is still the lack of a theoretical framework for summary-free ABC that (i) is unified, instead of discrepancy-specific, (ii) does not necessarily require to constrain the analysis to data generating processes and statistical models meeting specific regularity conditions, but rather facilitates the derivation of limiting properties that hold uniformly, and (iii) relies on verifiable assumptions that provide more explicit concentration bounds clarifying which factors govern the limiting behavior of the ABC posterior. We address this gap via a novel theoretical framework that introduces the concept of Rademacher complexity in the analysis of the limiting properties for discrepancy-based ABC posteriors, including in non-i.i.d. and misspecified settings. This yields a unified theory that relies on constructive arguments and provides more informative asymptotic results and uniform concentration bounds, even in those settings not covered by current studies. These key advancements are obtained by relating the asymptotic properties of summary-free ABC posteriors to the behavior of the Rademacher complexity associated with the chosen discrepancy within the family of integral probability semimetrics (IPS). The IPS class extends summary-based distances, and also includes the widely implemented Wasserstein distance and maximum mean discrepancy (MMD), among others. As clarified in specialized theoretical analyses of popular IPS discrepancies and via illustrative simulations, this new perspective improves the understanding of summary-free ABC
Energy communities - lessons learnt, challenges, and policy recommendations
Get PDFEnergy communities (ECs) are considered important in transitioning the energy system. They are of particular interest due to their
potential to empower citizens and support a more just energy transition. However, experiences from ECs remain limited and vary across
countries, thus raising questions on potential future advancements. In this article, we explore experiences from ECs in several European
countries to inspire discussions on further evolvement and improvements. Insights into lessons learned and key challenges within the
selected countries have been collected and analysed, and recommendations for advancing these efforts are provided to policy makers.
The results indicate that ECs are making progress in producing and sharing renewable energy while supporting a more just energy
transition by engaging a variety of actors within local communities. The challenges, however, often stem from limited national support
and difficulties in fully achieving diversity within engaged local communities. The recommendations stress the importance of building
on early learnings in community energy and further strengthening local anchoring to achieve a just transition. This in turn, generates
fertile ground for discussions on how to localize energy policy and reinforce a multi-level policy approach beyond the European and
national levels
L’évolution de l’institution du préfet en Italie de l’origine à nos jours
No full textL’évolution du rôle et de l’institution du préfet en Italie est addressée en examinant trois facteurs fondamentaux.
Le premier facteur est l’évolution du rôle du préfet en raison des changements
du contexte juridique et social de l’État italien et, en particulier, en raison des
transformations qui ont affecté l’administration italienne du système savoyard
à l’adoption de la Constitution républicaine.
Le deuxième facteur correspond aux fonctions actuelles du préfet, c’est-à-dire
ce que fait le préfet en Italie aujourd’hui, quelles sont ses missions, démontrant
la vitalité particulière de l’institution préfectorale, qui a su se réinventer au fil
des années, en assumant un rôle de plus en plus soutenu pour les collectivités
territoriales, par exemple dans la gestion des urgences environnementales et de
la crise migratoire.
Le troisième facteur renverra aux perspectives de réforme du préfet au
regard de l’évolution du système juridique et du récent débat politique en Italie
Time-varying risk aversion and international stock returns
No full textWe estimate aggregate, time-varying risk aversion inferred from options, stock returns and macroeconomic data for a panel of 8 countries. We document that, for most countries, the estimated risk aversion measure is counter-cyclical. Moreover, we show that estimated risk aversion forecasts monthly stock index returns up to 12 months ahead. This effect is statistically significant in panel regressions, and it survives the inclusion of additional control variables, such as an estimated of the variance risk premium, an investors’ sentiment index, and a measure of economic uncertainty. Finally, we show that risk aversion provides useful information to an investor who aims at timing the market. An investment strategy that uses the estimated time-varying risk aversion measure to solve a mean–variance asset allocation problem, delivers significantly positive returns
Stabilization of capacitated matching games
No full textAn edge-weighted, vertex-capacitated graph G is called stable if the value of a maximum-weight capacity-matching equals the value of a maximum-weight fractional capacity-matching. Stable graphs play a key role in characterizing the existence of stable solutions for popular combinatorial games that involve the structure of matchings in graphs, such as network bargaining games and cooperative matching games. The vertex-stabilizer problem asks to compute a minimum number of players to block (i.e., vertices of G to remove) in order to ensure stability for such games. The problem has been shown to be solvable in polynomial-time, for unit-capacity graphs. This stays true also if we impose the restriction that the set of players to block must not intersect with a given specified maximum matching of G. In this work, we investigate these algorithmic problems in the more general setting of arbitrary capacities. We show that the vertex-stabilizer problem with the additional restriction of avoiding a given maximum matching remains polynomial-time solvable. Differently, without this restriction, the vertex-stabilizer problem becomes NP-hard and even hard to approximate, in contrast to the unit-capacity case
Economic value of enhanced monofocal intraocular lenses for cataract surgery in Italy
Get PDFAim
Cataract is a prevalent health condition, primarily caused by aging, affecting approximately 95 million individuals worldwide. The only effective treatment currently involves surgically removing and replacing the crystalline lens with an artificial intraocular lens (IOL). Various IOLs are available, each with distinct characteristics, costs, and outcomes. This study aimed to assess the value of an enhanced monofocal IOL for cataract surgery, which has been shown to improve intermediate vision and reduce the need for spectacles during intermediate tasks, compared to a conventional monofocal IOL (standard of care), through a cost-utility analysis from both the National Healthcare Service (NHS) and societal perspectives in Italy.
Methods
A cost-utility model was developed incorporating both healthcare and nonhealthcare costs, as well as productivity losses, using data from a socio-economic questionnaire administered at three clinical centers in Italy. The questionnaire included the EuroQol 5D-5L to assess quality of life. National Healthcare Service costs were based on reimbursement tariffs.
Results
Over a 10-year horizon, estimated costs were 15,723 € (16,643 USD) for the standard IOL group and 11,190 € (11,845 USD) for the enhanced monofocal IOL group from the societal perspective. Since no significant differences in patients’ quality of life were observed between the two groups, the innovative IOL may be considered a cost-saving option compared to standard monofocal IOL. From the NHS perspective, only the intervention for lens implantation was considered, resulting in costs of 940 € (994.99 USD) and 900 € (952.65 USD) for enhanced monofocal IOL and standard IOL, respectively. In this perspective, enhanced monofocal IOL was dominated (more costly with the same QALYs) by standard IOL.
Conclusions
This study fills a literature gap by evaluating the cost-utility of enhanced monofocal IOLs for cataract surgery compared to standard IOLs. While enhanced monofocal IOL is dominated from the NHS perspective due to slightly higher direct healthcare costs, it is cost-saving from a societal perspective by reducing the overall economic burden with comparable patients’ quality of life. The broader benefits, including reduced reliance on corrective measures, visits and exams, formal and informal assistance, emphasize its societal value. This highlights the need for a holistic healthcare approach that balances long-term societal savings with short-term healthcare costs
El urbanismo y la ciudad
No full textL'articolo affronta i temi dell'urbanistica in prospettiva storica e con focalizzazione sul tema della smart city. Si propone una periodizzazione in cicli rispetto al rapporto con il territori
Literacy and financial education: private providers, public certification and political preferences
Get PDFFinancial education can influence the level of financial literacy. In many countries public authorities implement financial education policy by means of ex ante certification of both private and public providers of education activities. This article uses political economy, educational marketing and text analysis as complementary tools to offer a positive analysis of such setting. Being financial education a credence good and given the key assumption that financial literacy is a country state–contingent endowment that deteriorates, as a consequence of innovation, the third-party certification can be considered as a strategic governance solution. Yet, when a public agency acts as third-party certifier, political and bureaucratic incentives shape its action. In particular, political activism in financial education can be motivated by financial instability worries. Such theoretical relationship is empirically confirmed applying text analyses, and using financial education narrative as a proxy for activism both for the politicians of the European Parliament and the bureaucrats of the ECB in the period 1997–2024
Mitigating Inequality
Get PDFThis dissertation attempts to provide a better understanding of inequality drivers and potential policies that could help mitigate the effects of economic downturns. Given that large income inequality exacerbates recession impacts, my job market paper explores the role of minimum wage in mitigating earnings inequality through its impact on labor force participation rate (the main driver of widening earnings inequality in the bottom half of U.S. labor earnings distribution). I show that raising the minimum wage during a recession can in fact help reduce the decline in the labor force participation rate, mitigating in turn the overall contraction in consumer demand. My paper demonstrates that, in addition to policies that focus on replacing earnings of workers who lost their job during a recession, additional policies that help sustain employed workers' labor income are needed to help counteract the further rise in inequality.
Some of the long-run increase in income inequality in the US can also be partially attributed to the shift in the population age structure, which we show in my co-authored paper. We provide empirical evidence that the decline in the natural rate of interest can be explained equally well by either demographics or inequality. We also show that the trend in the stock market, driven by demographics, explains the rise in inequality.
Focusing on the stock market, my third paper analyses the role of equity-based pay in mitigating financial amplification effects of wage rigidity during downturns. Given the substantial use of equity based pay, the question arises as to what extent the ability to adjust the compensation structure can soften the impacts of a recession. My paper shows that the use of equity-based pay, by deferring part of labor expenses, helps stabilize firms' employment and save jobs, with the effects being more pronounced when access to external funding is more limited
Corruption and extremism
No full textThis paper shows that corruption generates extremism, but mainly on the opposition side. While corruption hurts all citizens, only voters on the minority side may desire to switch to a more extreme representative when they perceive a more corrupt political system. In our model, campaigning on a corruption scandal against the incumbent gives a higher winning probability for the opposition politician but simultaneously reduces expected future rents from
office. As extremist politicians normally are less likely to win against a moderate opponent, they have a stronger incentive to take a stand against corruption. Given that the side of the political minority has a lower chance of having their representative elected to office, they face a smaller opportunity cost of voting for extremists. Our main result is that minorities are more likely to react to corruption with more extremism. We provide causal evidence for this novel asymmetric prediction from Indonesia and Brazil