Mixing of MCMC algorithms

We analyse MCMC chains focusing on how to find simulation parameters that give good mixing for discrete time, Harris ergodic Markov chains on a general state space X having invariant distribution π. The analysis uses an upper bound for the variance of the probability estimate. For each simulation parameter set, the bound is estimated from an MCMC chain using recurrence intervals. Recurrence intervals are a generalization of recurrence periods for discrete Markov chains. It is easy to compare the mixing properties for different simulation parameters. The paper gives general advice on how to improve the mixing of the MCMC chains and a new methodology for how to find an optimal acceptance rate for the Metropolis-Hastings algorithm. Several examples, both toy examples and large complex ones, illustrate how to apply the methodology in practice. We find that the optimal acceptance rate is smaller than the general recommendation in the literature in some of these examples.     

Dread and Risk Elimination Premium for the Value of a Statistical Life

The value of a statistical life (VSL) is a widely used measure for the value of mortality risk reduction. As VSL should reflect preferences and attitudes to risk, there are reasons to believe that it varies depending on the type of risk involved. It has been argued that cancer should be considered a “dread disease,” which supports the use of a “cancer premium.” The objective of this study is to investigate the existence of a cancer premium (for pancreatic cancer and multiple myeloma) in relation to road traffic accidents, sudden cardiac arrest, and amyotrophic lateral sclerosis (ALS). Data were collected from 500 individuals in the Swedish general population of 50–74‐year olds using a web‐based questionnaire. Preferences were elicited using the contingent valuation method, and a split‐sample design was applied to test scale sensitivity. VSL differs significantly between contexts, being highest for ALS and lowest for road traffic accidents. A premium (92–113%) for cancer was found in relation to road traffic accidents. The premium was higher for cancer with a shorter time from diagnosis to death. A premium was also found for sudden cardiac arrest (73%) and ALS (118%) in relation to road traffic accidents. Eliminating risk was associated with a premium of around 20%. This study provides additional evidence that there exist a dread premium and risk elimination premium. These factors should be considered when searching for an appropriate value for economic evaluation and health technology assessment.     

To bid or not to bid

This paper discusses the importance of permanent customer relations for firms in an environment where bidding takes place. The analysis is first directed toward the bidding resources per order with special reference to the differences in order rate between permanent and non-permanent customers. The importance for bidding firms to keep close track of order rates for different customer groups is stressed here. In the succeeding analysis the bidding on requests from non-permanent customers is treated as investments in future orders. Here we note the dilemma of firms with low or zero profit margins, which are likely to bid on too many bids, thus incurring higher bidding costs than their more profitable competitors.     

Gender Equality in Europe: The Development of the Sustainable Development Goal No. 5 Illustrated by Exemplary Cases

Social Indicators Research - The inequality between genders is a problem virtually in all countries. A comparison among 28 nations of the European Union together with a data set corresponding to a...     

A QUARTET OF SEMIGROUPS FOR MODEL SPECIFICATION,ROBUSTNESS, PRICES OF RISK,AND MODEL DETECTION

A representative agent fears that his model, a continuous time Markov process with jump and diffusion components, is misspecified and therefore uses robust control theory to make decisions. Under the decision maker's approximating model, cautious behavior puts adjustments for model misspecification into market prices for risk factors. We use a statistical theory of detection to quantify how much model misspecification the decision maker should fear, given his historical data record. A semigroup is a collection of objects connected by something like the law of iterated expectations. The law of iterated expectations defines the semigroup for a Markov process, while similar laws define other semigroups. Related semigroups describe (1) an approximating model; (2) a model misspecification adjustment to the continuation value in the decision maker's Bellman equation; (3) asset prices; and (4) the behavior of the model detection statistics that we use to calibrate how much robustness the decision maker prefers. Semigroups 2, 3, and 4 establish a tight link between the market price of uncertainty and a bound on the error in statistically discriminating between an approximating and a worst case model. (JEL: C00, D51, D81, E1, G12)     

Communicating equality through policy documents: On legitimacy,double logic and stable translations

This article discusses gender mainstreaming (GMS) as a strategy to implement gender equality in public work organizations by analysing discourse in terms of the theoretical notions of translation and circulation in organizations to shed light on how gender equality and the mainstreaming strategy are formulated in the documents which govern the Swedish fire and rescue services. More specifically, it looks at how the goals regarding gender equality are circulated and translated. The results show that gender equality as a practice is created in the translation of national goals in terms of the local context and its specific gender equality challenges. Furthermore, the article discusses how vague formulations in the documents are stabilized through circulation between the government and the public agency in question. The results indicate the central role played by maintaining stable translations over time and the presence of a double logic of change in the processes, as well as the importance of legitimizing gender equality initiatives.