Measuring Educational Heterogeneity And Labor Quality: A Note

This paper investigates the magnitude of the mismeasurement that occurs when only a few education categories are used in the construction of a constant quality index for labor input. By employing a very comprehensive data set it is found that the error resulting from the omission of information on education is relatively small. The empirical results are thus supportive of the current state of practice of constructing indices of constant quality labor input.     

Calculation of ruin probabilities for a dense class of heavy tailed distributions

In this paper, we propose a class of infinite-dimensional phase-type distributions with finitely many parameters as models for heavy tailed distributions. The class of finite-dimensional phase-type distributions is dense in the class of distributions on the positive reals and may hence approximate any such distribution. We prove that formulas from renewal theory, and with a particular attention to ruin probabilities, which are true for common phase-type distributions also hold true for the infinite-dimensional case. We provide algorithms for calculating functionals of interest such as the renewal density and the ruin probability. It might be of interest to approximate a given heavy tailed distribution of some other type by a distribution from the class of infinite-dimensional phase-type distributions and to this end we provide a calibration procedure which works for the approximation of distributions with a slowly varying tail. An example from risk theory, comparing ruin probabilities for a classical risk process with Pareto distributed claim sizes, is presented and exact known ruin probabilities for the Pareto case are compared to the ones obtained by approximating by an infinite-dimensional hyper-exponential distribution.     

Trip-timing decisions with traffic incidents

This paper analyzes traffic bottleneck congestion when drivers randomly cause incidents that temporarily block the bottleneck. Drivers have general scheduling preferences for time spent at home and at work. They independently choose morning departure times from home to maximize expected utility without knowing whether an incident has occurred. The resulting departure time pattern may be compressed or dispersed according to whether or not the bottleneck is fully utilized throughout the departure period on days without incidents. For both the user equilibrium (UE) and the social optimum (SO) the departure pattern changes from compressed to dispersed when the probability of an incident becomes sufficiently high. The SO can be decentralized with a time-varying toll, but drivers are likely to be strictly worse off than in the UE unless they benefit from the toll revenues in some way. A numerical example is presented for illustration. Finally, the model is extended to encompass minor incidents in which the bottleneck retains some capacity during an incident.     

A Technique for Reducing Discretization Bias from Monte Carlo Simulations: Option Pricing under Stochastic Interest Rates

Abstract

Control variates are often used to reduce variability in Monte Carlo estimates and their effectiveness is traditionally measured by the so-called speed-up factor. The main objective of this paper is to demonstrate that a control variate can also be applied to reduce the bias stemming from the discretization of the state variable dynamics. This is particularly valuable when stochastic interest rate models are discretized, since bias reduction through more grid points is computationally expensive.     

Associations between risk judgments and demand for transport risk mitigation

The present study tested a hypothesized model regarding associations between risk sensitivity, risk perception, transport priorities, worry, and demand for risk mitigation in transport. An additional aim was to investigate differences in risk perception, worry, risk sensitivity, transport priorities, and demand for risk mitigation in age-groups, gender, and educational levels. A mail survey was conducted in a representative sample of the Norwegian public over 18?years (n?=?1947) in 2008. The response rate was 31%. The results showed that transport priorities were the strongest predictor of demand for risk mitigation. Risk perception seems to be mediated by worry. Risk sensitivity was directly associated with transport risk perception and, not as predicted, also directly with demand for risk mitigation. The two youngest age-groups (18–30 and 31–50?years) perceived the probabilities of transport accidents in private transportation as significantly larger and also judged other nontransport risks to be larger than those over 50?years of age. The youngest age-group was more worried about injuries from private transportation, but reported lower demands for risk mitigation. The findings merit further research into the relationship between risk perception and demand for risk mitigation. The results indicated that younger individuals were more worried about injuries and assessed the probability of accidents to be larger, while they report a lower demand for risk mitigation compared to older age-groups.     

Between dependence and deprivation: The interlocking nature of land alienation in Tanzania

Studies of accumulation by dispossession in the Global South tend to focus on individual sectors, for example, large‐scale agriculture or nature conservation. Yet smallholder farmers and pastoralists are affected by multiple processes of land alienation. Drawing on the case of Tanzania, we illustrate the analytical purchase of a comprehensive examination of dynamics of land alienation across multiple sectors. To begin with, processes of land alienation through investments in agriculture, mining, conservation, and tourism dovetail with a growing social differentiation and class formation. These dynamics generate unequal patterns of land deprivation and accumulation that evolve in a context of continued land dependency for the vast majority of the rural population. Consequently, land alienation engenders responses by individuals and communities seeking to maintain control over their means of production. These responses include migration, land tenure formalization, and land transactions, that propagate across multiple localities and scales, interlocking with and further reinforcing the effects of land alienation. Various localized processes of primitive accumulation contribute to a scramble for land in the aggregate, providing justifications for policies that further drive land alienation.