Cinzia Mortarino

Sequential market entries and competition modelling in multi-innovation diffusions

The diffusion of innovations for simultaneous processes cannot take into account and properly explain systematic perturbations due to competition-substitution effects if they are examined one by one. A first aspect in simultaneous competing diffusions is the distinction between simultaneous market entries (synchronic competition) and sequential entries (diachronic competition). In the latter case, the beginning of competition may upset the first entrant’s diffusion. A second important aspect in multiple competition is represented by the choice to model the word-of-mouth effect either at the category level (balanced model) or at the brand level, separating the within-brand effect from the cross-brand one (unbalanced model). In this paper, balanced models are studied, and we propose a model that allows for a change in the parameter values of the first entrant as soon as the second one enters the market. The resulting differential system has a closed-form solution that enables, through sales data, an empirical validation of the assumptions underlying the model structure, improving the forecasting accuracy. An application to pharmaceutical drug competition is discussed.

Duncan's model for X-control charts: sensitivity analysis to input parameters.

Duncans model is a well-known procedure to build a control chart with specific reference to the production process it has to be applied to. Although many papers report true applications proving the procedures noteworthy economic advantages over control charts set purely on the basis of standard statistical criteria, this method is often perceived only as an academic exercise. Perhaps the greater barrier preventing its practical application stems from the difficulty in making cost items explicit. In this paper a sensitivity analysis is proposed for misspecification in the cost parameters for optimal solutions of Duncans model. While similar contributions published in the literature perform sensitivity analyses with a one-factor-at-a-time scheme, the original contribution of this paper is represented by the focus given on interactions among changes in values of different cost parameters. The results obtained here denote that all factors significantly affect optimal solutions through quite complicated interactions. This should not, in our opinion, discourage the implementation of Duncans model, pointing conversely to its robust versions, already available in the current literature. Copyright

Pleural Mesothelioma: forecasts of the death toll in the area of Casale Monferrato, Italy

In the city of Casale Monferrato, the largest Italian factory that produced asbestos-cement goods was active from 1907 to 1985. Consequently, asbestos fibers scattered in the surrounding area and caused an enormous number of cases of pleural mesothelioma. Owing to the very long latency of this disease, many subjects have not exhibited its symptoms yet. The aim of this paper is to model and predict the future evolution of the number of deaths due to this disease among residents in the area around that city. The model used here is based on a cellular automata that is assumed to pass through three steps: exposure, contamination, and diagnosis. In this way, forecasts of the future evolution take into account the environmental conditions that changed over the last century because of different levels of plant activity. The model is fitted to annual diagnosis data from 1954 to 2008. Results show that deaths will not end until 2031 and that in the next two decades, at least 505 more subjects will be diagnosed with this disease.

Correction to the Paper “Optimal Product Launch Times in a Duopoly: Balancing Life-Cycle Revenues with Product Cost”

The aim of this note is to correct an error in the formulation of Theorem 1 by Savin and Terwiesch [Savin, S., C. Terwiesch. 2005. Optimal product launch times in a duopoly: Balancing life-cycle revenues with product cost. Oper. Res.53(1) 26--47].

An improved statistical test for historical linguistics

Historical linguistics needs procedures to evaluate the similarity between languages through the comparison of specific word lists drawn from the whole vocabulary. The main issue is to evaluate a fair threshold for the number of similar items beyond which it is sensible to reject the hypothesis of chance similarity. After a short review of papers dealing with that problem, in this paper an extension of those methods is proposed which exploits available data in a more efficient way. In particular, the exact distribution of the new test statistics is calculated and the power of the new procedure is compared with the power of the existing method.

Pre-launch forecasting of a pharmaceutical drug

Purpose The emergence of a pharmaceutical drug as a late entrant in a homogeneous category is a relevant issue for strategy implementation in the pharmaceutical industry. This paper aims to suggest a methodology for making pre-launch forecasts with a complete lack of information for a late entrant. Design/methodology/approach The diffusion process of the emerging entrant is estimated using the diffusion dynamics of pre-existing drugs, after an appropriate assessment of the drug’s entrance point. The authors’ methodology is applied to study the late introduction of a pharmaceutical drug in Italy within the category of ranitidine. Historical data of seven already active drugs in the category are used to assess and estimate ex ante the dynamics of a late entrant (Ulkobrin). Findings The results of applying the procedure to the ranitidine market reveal a high degree of accuracy between the ex post observed values of the late entrant and its ex ante mean predicted trajectory. Moreover, the assessed launch date corresponds to the actual date. Research limitations/implications The category has to be homogeneous to ensure a high degree of similarity among the existing drugs and the late entrant. For this reason, radical innovations cannot be forecast with this methodology. Originality/value The proposed approach contributes to the still challenging research field of pre-launch forecasting by estimating the dynamic features of a homogeneous category and exploiting them for forecasting purposes.

A forecasting model for drug utilization and expenditure integrating a Cellular Automata model with the Budget Impact Analysis approach. Preliminary results

Results The first-in-class emerging anti-diabetic dapagliflozin was selected and critically evaluated by the IHSP about 12 months before the European Marketing Authorization (MA). Other competitors already on the market were identified. A CA model describing the diffusion process of more than 200 Italian specialties of oral antidiabetic drugs (ATC A10B), sold between 2000 and 2014 has been developed and validated. A protocol for the identification of the real-world target population in the ARNO-CINECA database was set up on the grounds of the expected indication for dapaglifozin. The estimation of the budget impact of dapagliflozin is ongoing based on the estimation of market shares, through the application of the CA model, the analysis of the identified target population and the analysis of the potential variations in related healthcare costs for the treatment of type 2 diabetes, after the introduction of dapagliflozin.

Circular Dependence in a Multiresponse Mixed Model under a Split-Plot Design

It is well known how to analyse correctly data arising from auniresponse fixed or mixed effects model under a split-plot design. Many results are available for both canonical dependence pattern (compound symmetry) and more general patterns. Conversely, for the multiresponse case, there are only few results concerning the repeated measurements context. Some references are here given for amultiresponse analysis under multivariate compound symmetry. The aim of this paper is to propose a simple methodology for MANOVA testing procedures if a more general dependence pattern,i.e., circular autoregressive multiresponse dependence pattern, is assumed. Conservative thresholds are suggested in order to perform a powerful test even if only vague information is available about parameters appearing in this dependence pattern.

Extended V—robustness for Two-level Orthogonal Resolution V Designs

Extended V—robustness property allows to prove coincidence between OLSE and WLSE for parameters of a multiresponse linear model when a regular fraction of a 2k factorial design is performed (Guseo and Mortarino (1997)). With a similar assumption, the same result was also proved for Addelman’s non-orthogonal irregular fractions (Mortarino (1996)).