Optimal Retirement with Increasing Longevity

We develop an optimizing life‐cycle model of retirement with perfect capital markets. We show that longer healthy life expectancy usually leads to later retirement, but with an elasticity less than unity. We calibrate our model using data from the US and find that, over the last century, the effect of rising incomes, which promote early retirement, has dominated the effect of rising lifespans. Our model predicts continuing declines in the optimal retirement age, despite rising life expectancy, provided the rate of real wage growth remains as high as in the last century.     

Innovation and HRM: Absences and politics

This article analyses the role of HRM practices in the implementation of an innovative cross-functional approach to new product development (concurrent engineering, CE) in Eurotech Industries. Contrary to CE methodology stipulations, and despite supportive conditions, HRM received scant attention in the implementation process. Organizational power and politics were clearly involved in this situation, and this article explores how their play created such HRM ‘absences’. The article builds on a four-dimensional view of power in order to provide a deeper understanding of the embedded, interdependent and political nature of HRM practice and innovation.     

The Effect of Market Regimes on Style Allocation

We analyse time-varying risk premia and the implications for portfolio choice. Using Markov Chain Monte Carlo (MCMC) methods, we estimate a multivariate regime-switching model for the Carhart (1997) four-factor model. We find two clearly separable regimes with different mean returns, volatilities, and correlations. In the High-Variance Regime, only value stocks deliver a good performance, whereas in the Low-Variance Regime, the market portfolio and momentum stocks promise high returns. Regime-switching induces investors to change their portfolio style over time depending on the investment horizon, the risk aversion, and the prevailing regime. Value investing seems to be a rational strategy in the High-Variance Regime, momentum investing in the Low-Variance Regime. An empirical out-of-sample backtest indicates that this switching strategy can be profitable, but the overall forecasting ability for the regime-switching model seems to be weak compared to the iid model.     

A forecasting model for the market of competitive products

The classic way of performing a market forecast for industrial products implies an econometric analysis of the historical data of consumption and their projections into the future. The present work illustrates a fresh approach to the problem; the demand for the product under study is evaluated in a mathematical model which takes into consideration the technological and commercial characteristics of this product and correlates it with competitive and substitutive products. Competitiveness is measured by assigning merit scores to the characteristics of the different products, and calculating the relevant “weights of importance” on the basis of the historical consumptions. Forecasts of consumption are made by estimating the future scores of the characteristics and extrapolating the weights of importance. An example of complete application of the model to the textile market in Italy is included.     

A structured approach to conflict prediction in information systems strategy implementation

Organizational power and politics are the central issues of this paper. By developing a model of organizational power it is possible to determine whether an organizational change initiative is likely to be politically feasible. The formal model described has been derived largely from research reported in the social sciences. The modelling process involved using formal methods, in logic and entity relationship analysis, to discover an effective and consistent means of representing key organizational power concepts. The result is an advisory expert system called MP/L1 that can be employed by change agents to predict likely sources of potential resistance to major change initiatives and to suggest tactics that might be effective in combating anticipated resistance. Industrial experience with MP/L1 to date indicates that it has significant potential as a change management tool within the IS strategy-implementation domain. © 1998 John Wiley & Sons, Ltd.     

Organizational forms in the knowledge economy: a comparative institutional analysis

This paper provides a framework with which to analyze organizational forms in the knowledge economy. We focus on an important trade-off facing modern firms: firms can acquire the property of all the innovations developed by their employees and can greatly increase their profits, yet this type of private intellectual property rights regime can discourage the innovative effort of the very same workers. Allowing workers to carry their knowledge outside the firm eliminates this disincentive. Hence, strategic complementarities may exist between innovative partners and a disclosure driven intellectual property rights regime, and passive employees and a private intellectual property rights regime. An evolutionary game theoretic model demonstrates these strategic complementarities and shows when economies tend towards disclosure driven or private intellectual property rights regimes.     

Quality Uncertainty as Resolution of the Bertrand Paradox

It is well‐known that product differentiation eliminates the Bertrand paradox (i.e. marginal cost pricing under duopoly). While differentiation is often justified with reference to the consumer's ‘preference for variety’, the conditions under which such a preference is likely to arise are rarely considered. We investigate this question in a setting in which uncertainty about product quality can endogenously generate either convex or non‐convex preferences. We show that even when two goods are ex ante homogeneous, quality uncertainty can eliminate the Bertrand paradox.     

Confirming the timing of phase-based costing in oncology studies: a case example in advanced melanoma

Aims: The utilization of healthcare services and costs among patients with cancer is often estimated by the phase of care: initial, interim, or terminal. Although their durations are often set arbitrarily, we sought to establish data-driven phases of care using joinpoint regression in an advanced melanoma population as a case example.

Methods: A retrospective claims database study was conducted to assess the costs of advanced melanoma from distant metastasis diagnosis to death during January 2010–September 2014. Joinpoint regression analysis was applied to identify the best-fitting points, where statistically significant changes in the trend of average monthly costs occurred. To identify the initial phase, average monthly costs were modeled from metastasis diagnosis to death; and were modeled backward from death to metastasis diagnosis for the terminal phase. Points of monthly cost trend inflection denoted ending and starting points. The months between represented the interim phase.

Results: A total of 1,671 patients with advanced melanoma who died met the eligibility criteria. Initial phase was identified as the 5-month period starting with diagnosis of metastasis, after which there was a sharp, significant decline in monthly cost trend (monthly percent change [MPC]?=?–13.0%; 95% CI?=?–16.9% to –8.8%). Terminal phase was defined as the 5-month period before death (MPC?=?–14.0%; 95% CI?=?–17.6% to –10.2%).

Limitations: The claims-based algorithm may under-estimate patients due to misclassifications, and may over-estimate terminal phase costs because hospital and emergency visits were used as a death proxy. Also, recently approved therapies were not included, which may under-estimate advanced melanoma costs.

Conclusions: In this advanced melanoma population, optimal duration of the initial and terminal phases of care was 5 months immediately after diagnosis of metastasis and before death, respectively. Joinpoint regression can be used to provide data-supported phase of cancer care durations, but should be combined with clinical judgement.