Search results for "probability"
showing 10 items of 3417 documents
Analyzing environmental‐trait interactions in ecological communities with fourth‐corner latent variable models
2021
In ecological community studies it is often of interest to study the effect of species related trait variables on abundances or presence-absences. Specifically, the interest may lay in the interactions between environmental and trait variables. An increasingly popular approach for studying such interactions is to use the so-called fourth-corner model, which explicitly posits a regression model where the mean response of each species is a function of interactions between covariate and trait predictors (among other terms). On the other hand, many of the fourth-corner models currently applied in the literature are too simplistic to properly account for variation in environmental and trait resp…
On the foundations of statistics and decision theory
1983
Este trabajo es una exposicion elemental de los fundamentos de la teoria de la decision a un nivel de generalidad que cubre la mayor parte de las aplicaciones de la metodologia bayesiana. Se subraya el contenido intuitivo de los axiomas que se sugieren y de los resultados que se obtienen. Se argumenta que la inferencia estadistica es un caso particular de problema de decision al que puede aplicarse el razonamiento axiomatico que se expone
Ranking Scientific Journals Via Latent Class Models for Polytomous Item Response Data
2015
Summary We propose a model-based strategy for ranking scientific journals starting from a set of observed bibliometric indicators that represent imperfect measures of the unobserved ‘value’ of a journal. After discretizing the available indicators, we estimate an extended latent class model for polytomous item response data and use the estimated model to cluster journals. We illustrate our approach by using the data from the Italian research evaluation exercise that was carried out for the period 2004–2010, focusing on the set of journals that are considered relevant for the subarea statistics and financial mathematics. Using four bibliometric indicators (IF, IF5, AIS and the h-index), some…
Comments on “Unobservable Selection and Coefficient Stability
2019
Abstract–: We establish a link between the approaches proposed by Oster (2019) and Pei, Pischke, and Schwandt (2019) which contribute to the development of inferential procedures for causal effects in the challenging and empirically relevant situation where the unknown data-generation process is not included in the set of models considered by the investigator. We use the general misspecification framework recently proposed by De Luca, Magnus, and Peracchi (2018) to analyze and understand the implications of the restrictions imposed by the two approaches.
Incorporating big microdata in life table construction: A hypothesis-free estimator
2019
Abstract The IT revolution, now more than ever, offers a cheaper and faster way to collect, store, transmit and process data. Detailed microdata of dates of death, migration and birth are already becoming available for general populations. In this paper, we develop within the family of period-based estimators a new, assumption-free estimator for constructing life tables. The estimator proposed exploits all the detailed data available and is free of the theoretical inconsistencies that the estimators currently used by most official statistical agencies have. We compute the proposed estimator for a real database and test the suitability of the hypotheses on which the estimators used so far re…
Delay in claim settlement and ruin probability approximations
1995
We introduce a general risk model for portfolios with delayed claims which is a natural extension of the classical Poisson model. We investigate ruin problems for different premium principles and provide approximations for the ruin probability. We conclude with some specific models, for example, for IBNR portfolios and portfolios where the pay-off process depends on the claim size.
Power laws and the market structure of tourism industry
2013
In this article, we use both graphical and analytical methods to investigate the market structure of one of the world’s fastest growing industries. For the German and Italian datasets, we show that the size distribution of tourism industry is heavy-tailed and consistent with a power-law behavior in its upper tail. Such a behavior seems quite persistent over the time horizon covered by our study, provided that during the period 2004–2009, the shape parameter is always in the vicinity of 2.5 for Germany and 2.6 for Italy. Size of the tourism industry has been proxied by the lodging capacity of hotel establishments: hotels, boarding houses, inns, lodging houses, motels, apartment hotels, touri…
Combining the intensity and sequencing of the poverty experience:a class of longitudinal poverty indices
2011
Summary Traditional measures of the persistence of poverty do not devote enough attention to the sequence of spells of poverty. We propose a new class of indices which measures the severity of chronic poverty, taking into account the way in which spells of poverty and non-poverty follow one another along individual life courses. All the years spent in poverty concur with the measurement of the persistency of poverty, albeit with a decreasing contribution provided that the distance between two consecutive spells of poverty becomes longer. Moreover, the distance from the poverty line and the poverty persistence probabilities are explicitly taken into account. A macrolevel index, which allows …
Replication invariance on NTU games
2001
Two concepts of replication (conflictual and non-conflictual) are extended from the class of pure bargaining games to the class of NTU games. The behavior of the Harsanyi, Shapley NTU, Egalitarian and Maschler-Owen solutions of the replica games is compared with that of the Nash and Egalitarian solutions in pure bargaining games.
Using Parametric Bootstrap to Introduce and Manage Uncertainty: Replicated Loaded Insurance Life Tables
2019
Insurance companies develop loaded life tables to protect themselves against deviations, for example, in the number of expected deaths or in the (residual) expectation of life of their insured. In ...