This article is concerned with the analysis of correlated count data. A class of models is proposed in which the correlation among the counts is represented by correlated latent effects. Special cases of the model are discussed and a tuned and efficient Markov chain Monte Carlo algorithm is developed to estimate the model under both multivariate normal and multivariate-t assumptions on the latent effects. The methods are illustrated with two real data examples of six and sixteen variate correlated counts.
In Switzerland the new law on health insurance, effective since 1996, introduced pro competitive changes in the market of sickness funds. The legislator expected high mobility between sickness funds of both healthy and sick insured as open enrolment was introduced with the new law. That is why the risk adjustment scheme, that was already introduced 1993, was limited until 2005. However, consumer mobility remained low and risk selection strategies are still profitable, since risk-adjustment is based only on demographic variables. This paper describes risk adjustment, consumer mobility, risk selection activities of sickness funds and the impact of imperfect risk adjustment on the development of HMO and PPO models. The paper concludes with a description of the current political and scientific discussion in Switzerland.
From the mid-1990s citizens in Belgium, Germany, Israel, the Netherlands and Switzerland have a guaranteed periodic choice among risk-bearing sickness funds, who are responsible for purchasing their care or providing them with medical care. The rationale of this arrangement is to stimulate the sickness funds to improve efficiency in health care production and to respond to consumers’ preferences. To achieve solidarity, all five countries have implemented a system of risk-adjusted premium subsidies (or risk equalization across risk groups), along with strict regulation of the consumers’ direct premium contribution to their sickness fund. In this article we present a conceptual framework for understanding risk adjustment and comparing the systems in the five countries. We conclude that in the case of imperfect risk adjustment—as is the case in all five countries in the year 2001—the sickness funds have financial incentives for risk selection, which may threaten solidarity, efficiency, quality of care and consumer satisfaction. We expect that without substantial improvements in the risk adjustment formulae, risk selection will increase in all five countries. The issue is particularly serious in Germany and Switzerland. We strongly recommend therefore that policy makers in the five countries give top priority to the improvement of the system of risk adjustment. That would enhance solidarity, cost-control, efficiency and client satisfaction in a system of competing, risk-bearing sickness funds.
We present results of a negative binomial model on the determinants of the number of days of absence in a given year for a sample of 2049 workers drawn from three factories. We find evidence of the terms of the remuneration contract being important and we offer an interpretation of the differential effect of the company sickpay scheme on the behaviour of workers contracted to work four or five days a week.
We discuss regression models for ordered responses, such as ratings of bonds, schooling attainment, or measures of subjective well-being. Commonly used models in this context are the ordered logit and ordered probit regression models. They are based on an underlying latent model with single index function and constant thresholds. We argue that these approaches are overly restrictive and preclude a flexible estimation of the effect of regressors on the discrete outcome probabilities. For example, the signs of the marginal probability effects can only change once when moving from the smallest category to the largest one. We then discuss several alternative models that overcome these limitations. An application illustrates the benefit of these alternatives.
This paper examines the determinants of mergers and bankruptcies, using firm level data from the Swiss Business Census and the Dun & Bradstreet exit database for Switzerland (1995-2000). Employing duration analysis, we find considerable differences in the determinants of mergers and bankruptcies, in particular with respect to firm size, location and the impact of macroeconomic conditions. Our results support the notion that mergers are often undertaken to seize growth opportunities.
Regulation fostering Managed Care alternatives in health insurance is spreading. This work reports on an experiment designed to measure the amounts of compensation asked by the Swiss population (in terms of reduced premiums) for Managed-Care type restrictions in the provision of health care. It finds that restrictions on the freedom of physician choice would require an average compensation of more than one-third of the premium, while generic substitution even meets with a small willingness to pay. Marked preference heterogeneity is an argument against regulation imposing uniformity of contract in Swiss social health insurance.
This paper provides evidence on the relation between the intensity of product market competition and the probability of exit. We adopt a natural experiment approach towards analyzing the impact of a tightening of Swiss antitrust legislation on exit probabilities. Based on a sample of more than 68,000 firms from all major sectors of the Swiss economy, we find that the exit probability of nonexporting firms increased significantly, whereas the exit probability of exporting firms remained largely unaffected. Our results support the notion that there is a positive relationship between the intensity of product market competition and the probability of exit.
This paper examines the e®ects of introducing competition into monopolized network industries on prices and infrastructure quality. Analyzing a model with reduced-form demand, we ¯rst show that deregulating an integrated monopoly cannot simultaneously decrease the retail price and increase infrastructure quality. Second, we derive conditions under which reducing both retail price and infrastructure quality relative to the integrated monopoly outcome increases welfare. Third, we argue that restructuring and setting very low access charges may yield welfare losses, as infrastructure investment is undermined. We provide an extensive analysis of the linear demand model and discuss policy implications.
