A Monte Carlo method for filtering a marked doubly stochastic Poisson process

The author provides an approximated solution for the filtering of a state-space model, where the hidden state process is a continuous-time pure jump Markov process and the observations come from marked point processes. Each state k corresponds to a different marked point process, defined by its conditional intensity function λ _k (t). When a state is visited by the hidden process, the corresponding marked point process is observed. The filtering equations are obtained by applying the innovation method and the integral representation theorem of a point process martingale. Since the filtering equations belong to the family of Kushner–Stratonovich equations, an iterative solution is calculated. The theoretical solution is approximated and a Monte Carlo integration technique employed to implement it. The sequential method has been tested on a simulated data set based on marked point processes widely used in the statistical analysis of seismic sequences: the Poisson model, the stress release model and the Etas model.     

Tools for evaluating EU agricultural policies: An integrated approach

The aim of this paper is to propose a theoretical “multi-phase” strategy for analysing in dynamic terms the territorial impact of agricultural and environmental EU policy measures. This approach should also allow to evaluate the adjustment capability of farms as a function of the characteristics of different territories. The proposed methodology is illustrated by an example using data relative to the 41 provinces of Northern Italy. In the first step, a multivariate statistical analysis (MSA) consisting in Principal Component Analysis and Cluster Analysis leads to the identification of homogeneous clusters of territorial units. The territorial mapping is conditional to a predetermined set of indicators that takes into account different aspects of agricultural development. In a second step, Positive Mathematical Programming (PMP) allows to introduce the impact of agricultural policies (compensatory payments, price changes, etc.) returning different scenarios of land use and agricultural profitability. According to the outputs of the PMP, the third step consists in a new MSA for detecting any changes in the territorial mapping. Convergence analysis can then synthesise the impact of the different policy options.     

Effects of sharing the parental leave on pensioners’ poverty and gender inequality in old age: A simulation in IFSIM

Female old age poverty is affected by family policy reforms which are meant to promote gender equality when young. Using our in house agent based simulation model IFSIM we show that sharing equally the parental leave can increase or reduce poverty among elderly women depending on the macro and behavioural (i.e. labour supply) responses that the reform off-sets. In general, the reform can be good for highly educated women, who will have an incentive to work more full time thanks to their higher earnings, which can compensate any loss in household income due to the man's staying home. For lower educated however, work might not pay as much and a reduction in labour supply might actually ensue (e.g. to reduce childcare costs). This will reduce also their pension rights at retirement. Furthermore, keeping men at home might slow down economic growth, and consequently growth of income pension accounts will be lower. This effect, combined with lower pension contributions (due to reduced labour supply), might result in higher poverty rates for women with lower education, compared to a scenario where the woman takes the whole leave. Other policies, such as more subsidised child care, might be an alternative worth considering to reduce female poverty in old age more evenly across educational levels.     

The Fertility Transition and Family Urban Income Distribution in Colombia*

This paper examines the effect of social and demographic changes on family income distribution in the largest Colombian cities between 1967 and 1968 and 1984 and 1985, two periods representing the conditions before and after Colombia's sharp fertility decline. The results indicate that urban family income distribution worsened between the two periods, when income shares from the middle-income groups declined while those received by the richest 10 percent increased and the shares received by the poorest 50 percent were unchanged. A decomposition of the Theil index revealed that the deterioration in urban family income inequality could be traced to groups whose representation in the population increased, namely: households with more educated heads, with working wives, with smaller families, and with fewer children.     

Gender, partner violence, and perceived family functioning among a sample of Vietnam veterans

This study examined partner violence and perceived family functioning among a sample of 298 male veterans and their female partners. Partner violent men were higher than partner violent women on measures of partner violence severity, although differences did not reach statistical significance. Among couples experiencing unidirectional violence, female victims of partner violence reported significantly poorer family functioning than male victims of partner violence. Data appear to suggest that the effects of male-perpetrated partner violence on perceived family functioning may be larger than that of female-perpetrated partner violence.     

Let's stay close: An examination of the effects of imagined contact on behavior toward children with disability

In line with current developments in indirect intergroup contact literature, we conducted a field study using the imagined contact paradigm among high-status (Italian children) and low-status (children with foreign origins) group members (N = 122; 53 females, mean age = 7.52 years). The experiment aimed to improve attitudes and behavior toward a different low-status group, children with disability. To assess behavior, we focused on an objective measure that captures the physical distance between participants and a child with disability over the course of a five-minute interaction (i.e., while playing together). Results from a 3-week intervention revealed that in the case of high-status children imagined contact, relative to a no-intervention control condition, improved outgroup attitudes and behavior, and strengthened helping and contact intentions. These effects however did not emerge among low-status children. The results are discussed in the context of intergroup contact literature, with emphasis on the implications of imagined contact for educational settings.     

Traces in the shadow: Occupational outcomes of previously undocumented migrants in Italy

Using a representative sample of currently legal third-country immigrants in Italy, obtained from the Social Condition and Integration of Foreign Citizens survey, this article examines the long-term labour market consequences of previous undocumented spells. First, formerly undocumented immigrants are identified using retrospective information on respondents' legal status. Second, immigrants are classified according to the duration of irregular spells before the achievement of the first residence permit. Third, current labour market outcomes are investigated to account for the endogeneity underlying the previous undocumented history. Results show that even though formerly undocumented immigrants are more likely to participate in the labour market, they are more likely to be employed in underqualified occupations than continuously legal immigrants. The duration of the irregular experience affects occupational qualification negatively, among both men and women. The lack of legal entry channels and policies to plan and regulate migration to Italy may reinforce labour market segmentation, exposing migrants to long-term occupational downgrade.     

Quantitative risk assessment of rabies being introduced into mainland France through worldwide noncommercial dog and cat movements

France has been rabies-free among nonflying mammals since 2001. Despite this status, the rabies virus has been introduced several times through noncommercial pet movements, posing a threat of infection by this 100%-lethal zoonosis among local animal and human populations. To quantify the risk of rabies being introduced through worldwide noncommercial dog and cat movements, we performed a quantitative risk assessment using stochastic scenario tree modeling. The mean annual probability of at least one rabies introduction incident was 0.35 (median: 0.24, 90% prediction interval (PI) [0.04; 0.98]) and the mean annual number of rabies-infected pets introduced through pet movements was 0.96 (median: 0.27, 90% PI [0.04; 3.88]). These results highlight a nonnegligible, even high risk due to the associated consequences of such events. In alternative scenario testing, preventive anti-rabies vaccination proved to be an effective measure since removing the vaccination requirement led to a > 15-fold increase in risk. The serological testing requirement had less of an effect (approximately two-fold increase when removed) and the posttest waiting period to ensure that antibodies were not linked to an infection had a negligible effect. Any change in pet owner compliance, especially regarding vaccination, could have a major impact on the risk. This study also shows that reinforced border control staff training could be more effective in reducing risk than more frequent checks. These results provide quantitative data for assessing the probability of the rabies virus entering France, and could help policymakers decrease this risk in rabies-free areas.     

Cross-country disparities in skill premium and skill acquisition

Skilled individuals are rewarded more in poor than in rich countries. Why aren't more individuals acquiring skills in poor countries? We document that the unemployment rate of the skilled net of that of the unskilled decreases with a country's level of development. Using a matching model of occupational choice and skill acquisition, we quantify the role of barriers to enter entrepreneurship for these unemployment rates, skill premium and acquisition. The cross-country correlation between skill premium and acquisition decreases by 45% when each country's gap to the US in the entrepreneurship barrier is decreased enough to even the unemployment differential.