Statistical matching is a technique which can be applied when one wants to investigate the joint relationship between two variables that are observed in different datasets, using one or more...Show moreStatistical matching is a technique which can be applied when one wants to investigate the joint relationship between two variables that are observed in different datasets, using one or more variables that overlap in both datasets. This joint relationship cannot be estimated without relying on assumptions or additional data. Classically, statistical matching is based on the Conditional Independence Assumption (CIA) which asserts the non-overlapping variables to be independent given the overlapping variable. This assumption is inflexible, untestable and often does not hold. The current project proposes to use an approach based on the Instrumental Variable Assumption (IVA). An instrumental variable is a variable that, given the value of some mediating variable, has no effect on some outcome variable. In the context of statistical matching this gives rise to three scenarios: the mediating variable overlaps, the outcome variable overlaps, or the instrumental variable overlaps. The IVA approach is more flexible than the CIA approach. This is because the IVA approach does not make any assumptions on which variable is the overlapping variable, whereas the CIA always conditions on the overlapping variable. The aims of the current study were twofold: 1) how does the IVA approach perform when the assumption is violated to various degrees and 2) how does the IVA approach compare to the CIA approach. To answer these questions, a simulation study was performed. For each scenario, joint probabilities of the non-overlapping variables were estimated under both the IVA and the CIA in populations which violate the IVA to various degrees. Measures for the bias, accuracy and precision were estimated and compared. The results indicate that the IVA approach is moderately robust against slight violations of the assumption. When the IVA is not violated, estimations are unbiased and for all matching scenarios the method outperforms the CIA. When the IVA is violated it is advisable to rely on the CIA, since results of the current simulation study suggest the CIA to be more robust against violations in general.Show less
In dit onderzoek wordt het effect van de mate van het vertrouwen in de overheid op verschillende burgerparticipatievormen onderzocht. Uit het onderzoek blijkt dat er een sterk positief effect is...Show moreIn dit onderzoek wordt het effect van de mate van het vertrouwen in de overheid op verschillende burgerparticipatievormen onderzocht. Uit het onderzoek blijkt dat er een sterk positief effect is van het vertrouwen in de overheid op het stemmen tijdens nationale en lokale verkiezingen. Met betrekking tot het meedoen aan demonstraties en het ondertekenen van petities is er geen duidelijk effect zichtbaar.Show less
This study analyses the role of issue saliency in the relationship between the retrenchment of the welfare state and the electoral outcomes of government parties in the next election. The role of...Show moreThis study analyses the role of issue saliency in the relationship between the retrenchment of the welfare state and the electoral outcomes of government parties in the next election. The role of issue saliency is tested by a statistical analysis across 25 European countries between 2001-2021. Three welfare state indicators, healthcare, pensions and unemployment, are used to see if their effect on electoral outcomes changes when they are more or less salient. The analysis shows a correlation between issue saliency and a positive effect of retrenchment on electoral outcome. Situations of budget constraints can explain the positive effects of electoral outcomes on electoral outcomes. We conclude that issue saliency is an accelerator for the effect the welfare state has on electoral results. Furthermore, we can conclude that budget constraints are an explanatory factor in why retrenchment measures positively affect electoral outcomes.Show less
This thesis investigates the daily life of an early medieval community in Central Italy by focusing on the skeletal collection (n = 66) from the ancient site of Satricum dating between the 9th and...Show moreThis thesis investigates the daily life of an early medieval community in Central Italy by focusing on the skeletal collection (n = 66) from the ancient site of Satricum dating between the 9th and 11th century AD, to advance our understanding of this everchanging period. The research employs the study of paleopathology, with a focus on osteoarthritis (OA), osteochondritis dissecans (OD), and periosteal new bone growth (PNB). The skeletal analyses revealed a high prevalence of joint degeneration, particularly in the spine, hip, shoulder, and elbow, while also PNB was recorded in relatively high numbers. The findings suggest that Satricum was a small, self-reliant community engaged in agricultural practices with ongoing physiological stressors. However, the presence of OA might have been influenced by both activity and genetic predisposition due to the long duration of the community settling in Satricum. The study also explored the impact of sex and age. The osteological assessment indicated a potential surplus of males, aligning with demographic patterns of early medieval times, while the identified females showed no distinctive activity markers, prompting further investigation into the "missing women" concept of the Middle Ages. The presence of only five subadults also raised questions about community beliefs, suggesting a potential societal distinction for individuals under the age of seven since no social separation was recognized between the adults and juveniles over that age. Furthermore, the funerary practices exhibited potential indicators of a Christian belief system, such as burial orientation and the absence of grave goods. The reuse of a Roman villa with a possible apsis also hinted at the presence of an ecclesial building. Comparisons with other Central Italian sites of the same period (Albano, Santa Severa, and Colonna) highlighted pathological and demographic commonalities. Therefore, in the broader context, this research contributes to existing knowledge by confirming scholar’s theories about life in rural medieval Central Italy. Finally, this study emphasizes the significance of investigating previously unstudied skeletal collections because these findings not only deepen our understanding of Satricum but also provide a foundation for future research, encouraging diverse approaches to further unravel the complexities of this ancient community.Show less
Since the formation of the contemporary Northern-Spanish autonomic community of Cantabria in 1981 the Iron Age has become increasingly important for its regional identity, symbolically embedded in,...Show moreSince the formation of the contemporary Northern-Spanish autonomic community of Cantabria in 1981 the Iron Age has become increasingly important for its regional identity, symbolically embedded in, for example, its name and flag. Although this in itself can be viewed as problematic, it also fuelled more archaeological investigations into Iron Age Cantabria. These investigations have mainly been focused on Iron Age hillforts of which currently approximately fourty-three (43) can be found throughout the autonomic community. The relatively late development of this field of study is one of the reasons why this number is significantly lower than the other northern Spanish autonomic communities of Asturias and Galicia. Simultaneously, Eucalyptus plantations have become the dominant form of forestation covering approximately 8% of total ground surface and forming 19% of the total amount of forests in Cantabria. This vegetation cover is found predominantly in the coastal region, where few of the identified Iron Age hillforts are found and where the plantations encroach on identified hillforts, making identification of new hillforts more difficult. While new digital tools and data for cultural resource management have become available, such as Light Detection and Ranging (LiDAR) and Geographic Information Systems (GIS), their usage have been limited in this region. To address this issue the research poses the question: ‘How can available methods and tools of archaeological prospection and cultural heritage management be used in an integrated workflow to find, map and preserve Iron Age hillforts under Eucalyptus plantations in Cantabria?’. The proposed integrated workflow consists of narrowing down suitable locations for Iron Age hillforts through object-based predictive modelling (OBPM) and subsequently remote prospection of those locations to identify potential features associated with archaeological sites. To test this approach it has been put into practice. The proposed workflow proved effective, but has also shown limitations. The parameters chosen are most-likely not solely relevant for Iron Age hillforts, consisting out of Geomorophon, incoming visibility-index and out-going visibility index. Also the research focus on Eucalyptus plantations showed a variability of noise in the Digital Elevation Model (DEM) for locations under Eucalyptus plantations, sometimes impeding readability of those areas. Nevertheless, the use of Sky View Factor (SVF) and the sufficiently narrowed down study area still proved effective in finding and documenting possible archaeological features, of which fifty (50) different locations have been identified with a variation of characteristics, all adhering to the set parameters. This suggests that the proposed integrated workflow is currently an effective tool in the finding, mapping and preserving archaeological sites near or encroached by Eucalyptus plantations.Show less
Social media has become an integral component of public agencies and digital diplomacy. Prior scholars have emphasised the significance of social media in International relations (IR), discussing...Show moreSocial media has become an integral component of public agencies and digital diplomacy. Prior scholars have emphasised the significance of social media in International relations (IR), discussing its advantages and difficulties. Nevertheless, in terms of public administration, there is a gap in their management, namely, in understanding how to use different platforms and the significance of social media content in engaging with the public. This research delves into the field of digital Diplomacy, examining the strategic use of social media content by the European Union’s diplomatic missions based in Athens, focusing on engagement with the public. The mixed-method study examined how diplomatic missions use social media content to engage with the public by analyzing original posts on Twitter/X and Facebook and conducting semi-structured interviews with experts and diplomats from EU Ministries of Foreign Affairs (MFAs) and embassies. The findings revealed that the EU embassies tend to employ posts that promote the countries’ image and interests’ indicators of Symbolic representation. In addition,they demonstrate a preference for Transparency by regularly sharing content that aligns with the policies, daily agenda and activity of the MFAs or embassies. The analysis using the Engagement Index (EI) results is noteworthy as it signifies an enhanced public connection with Coproduction content. Finally, the study reveals the strategic use of the platforms and the content for effective public engagement. Future researchers can delve into new directions by exploring other platforms or focusing on public reaction via sentimental analysis. In summary, this research emphasizes the importance of social media in diplomatic missions' external communication and advances the field by implementing the framework in digital diplomacy, particularly in the EU.Show less
The behavioral theory of the firm lacks a comprehensive understanding of issue prioritization, particularly when multiple issues are performing below aspiration levels, or resources are limited....Show moreThe behavioral theory of the firm lacks a comprehensive understanding of issue prioritization, particularly when multiple issues are performing below aspiration levels, or resources are limited. This study investigates the prioritization of eGovernment initiatives, considering budget constraints and the emphasis on historical versus social aspiration levels. Two theoretical expectations were developed: 1) the prioritization of historical versus social aspiration levels, and 2) the prioritization of eGovernment initiatives under budget constraints. Semi-structured interviews with 9 public officials from the Directorate-General for Economic Activities in Portugal were conducted to assess the expectations. The thematic analysis revealed that public officials do not change the priorities of eGovernment initiatives based on budget constraints and predominantly prioritize social aspirations over historical ones. This study highlights the importance of pragmatism driven by necessity alongside creativity. The findings have implications for issue prioritization, performance feedback, cutback management, and public administration literature in general. Future research should expand the study to include coercive aspiration levels, less salient issues, different countries, and different public organizations. Additionally, preferences and public sector motivation can be included as moderators, and employing a mixed-methods approach could be beneficial.Show less
Recent crises have brought asylum-migration to the forefront of political debate in Europe. There has been significant discourse in academic and policymaking spheres concerning migratory pull...Show moreRecent crises have brought asylum-migration to the forefront of political debate in Europe. There has been significant discourse in academic and policymaking spheres concerning migratory pull factors; in particular whether prospective socio-economic entitlements in destination countries are determinants of asylum applicants’ destination choice. Employment rights feature prominently in these discourses, yet few studies directly examine the relationship between labour market access and asylum inflows. This paper exploits Ireland’s transposition of the Recast Reception Conditions Directive in 2018, which ended a comprehensive ban on asylum applicants’ access to the labour market, in order to study the effects of labour market access on the magnitude and demographic composition of asylum applications. Using difference in difference and regression discontinuity methodologies, this paper finds that the labour market access reform caused an increase in the number of asylum applications and in the proportion of working-age applicants in Ireland. These findings contribute to a small body of quasi-experimental literature on the determinants of asylum inflows to destination countries.Show less
De opkomst van protesten, demonstraties en proteststemmen in Europa als gevolg van groeiende onvrede, wantrouwen en een gevoel niet gehoord te woorden door ‘de politieke’ en/of ‘de overheid’ raken...Show moreDe opkomst van protesten, demonstraties en proteststemmen in Europa als gevolg van groeiende onvrede, wantrouwen en een gevoel niet gehoord te woorden door ‘de politieke’ en/of ‘de overheid’ raken aan het fundament waar democratie als politiek- bestuurlijk systeem op is gebaseerd. Een democratie bestaat immers in ieder geval uit volkssoevereiniteit en meerderheidsheerschappij. Responsiviteit maakt hier een essentieel onderdeel van uit aangezien dit gaat over de mate waarin het handelen van de overheid, zoals vastgelegd in beleid en wet-en regelgeving, in overeenstemming is met de wil van het volk. Hoewel er veel onderzoek bestaat naar (overheids)responsiviteit en diens werking aan de ene kant en onderzoek naar politieke partijen en diens (electorale) werking aan de andere kant, is er geen recent en gedegen onderzoek dat deze twee min of meer gescheiden onderzoekvelden in de Europese context combineert. Dit onderzoek kijkt daarom als een van de eerste, aan de hand van een grote steekproef van Europese landen en een focus op herverdeling als concreet beleidsissue, naar de (mediërende) rol die politieke partijen spelen in de link tussen publieke opinie en (overheids)beleid via de centrale onderzoeksvraag: wat is het effect van voorkeuren van burgers ten aanzien van herverdeling op het daadwerkelijk gevoerde beleid van nationale overheden ten aanzien van herverdeling en in welke mate verloopt dit effect via de standpunten van politieke partijen ten aanzien van herverdeling? Door middel van Granger causaliteit in SPSS wordt een unieke dataset, bestaande uit data van de ESS, CHES, OECD en WDI, geanalyseerd. Uit het onderzoek blijkt, tegen de verwachtingen in, dat de voorkeur van burgers ten aanzien van herverdeling geen effect heeft op het daadwerkelijk gevoerde beleid van nationale overheden ten aanzien van herverdeling en dat dit effect niet verloopt via de stadpunten van politieke partijen ten aanzien van herverdeling. Deze onverwachte uitkomst roepen veel vragen op die het uitgangspunt zouden kunnen zijn voor toekomstig onderzoek.Show less
What is the effect of AI technology usage by bureaucrats under problematic conditions on the perceived legitimacy of bureaucratic decisions? Scholars argue that AI usage potentially exacerbates the...Show moreWhat is the effect of AI technology usage by bureaucrats under problematic conditions on the perceived legitimacy of bureaucratic decisions? Scholars argue that AI usage potentially exacerbates the negative consequences of misused bureaucratic discretion. Others suggest that AI usage might curtail bureaucratic discretion and increase outcomes of equity and efficiency. Existing empirical research demonstrates no significant difference between the perceived legitimacy of AI-assisted and human decision-making. This study aims to determine the effect of AI usage on the perceived legitimacy of bureaucratic decisions made under problematic principal-agent dilemma conditions. This effect is assessed across 96 survey respondents from the University of Leiden and the University of Amsterdam using experimental factorial survey analysis. The results of this research indicate that AI usage in decision-making has a significant positive effect on perceived legitimacy (p < 0.001). The main implication of this research is that AI usage can plausibly alleviate the impact of consequential bureaucratic decisions on perceived legitimacy by obscuring bureaucratic discretion. A second implication is that AI usage in bureaucratic decision-making exerts a notable effect on the perceived efficiency of bureaucratic decisions.Show less
Prediction models play a paramount role in various fields such as psychology and medicine, where the aim is to maximize predictive performance while ensuring high interpretability and stability....Show morePrediction models play a paramount role in various fields such as psychology and medicine, where the aim is to maximize predictive performance while ensuring high interpretability and stability. Prediction rule ensembles are a recent statistical learning method that address the black-box problem from common machine learning methods. First, an ensemble of trees is fitted, and by employing sparse regression, such as the lasso, only a subset of those trees is retained in the final ensemble, enhancing interpretability. However, the lasso suffers from drawbacks, considering that the optimal penalty parameter for variable selection may lead to an over-shrinkage of large coefficients. This study investigates if accuracy, sparsity, and stability of prediction rule ensembles can be improved by using the adaptive or relaxed lasso, or their combination. In the adaptive lasso, weight parameters are assigned to each coefficient in the penalty term, while in the relaxed lasso the lasso coefficients are debiased towards unpenalized values. In addition, in this study we compared if the results differ if the model selection was based on the lambda- 1se or lambda-min criterion and between continuous and binary outcomes. For this, the models were evaluated on nine benchmark datasets using repeated 10-fold cross-validation. The results show that all lasso variations improve model sparsity significantly while maintaining high accuracy, but at the cost of stability. The relaxed and adaptive lasso select sparser models than the standard lasso while achieving good stability of variable selection, but at the cost of less stable predictions. The relaxed adaptive lasso yields the sparsest model, but is the most unstable. Regarding lambda criterion, for continuous outcomes the lambda-minimum criterion leads to highly unstable results and diminishes the effect of lasso approach used. For binary outcomes, the lambda-1se criterion only improves accuracy and sparsity, but not stability, while for continuous outcomes it improves all performance diagnostics.Show less
