Economic modelling of costs associated with outcomes reported for type 2 diabetes mellitus (T2DM) patients in the CANVAS and EMPA-REG cardiovascular outcomes trials

Aims: To model direct medical costs associated with reductions in cardiovascular disease (CVD) events in T2DM patients reported in the CANVAS and EMPA-REG trials, which assessed the cardiovascular safety of canagliflozin and empagliflozin, respectively.

Materials and methods: Costs were modeled from a US managed care organization (MCO) perspective for the CVD outcomes included in both trials: three-point major adverse cardiovascular event (MACE) and its components (cardiovascular-related death, nonfatal myocardial infarction, nonfatal stroke), as well as heart failure requiring hospitalization. The rate of CVD events averted (difference between study drug and placebo) was projected to the portion of an MCO T2DM population matching the respective trial’s inclusion criteria. A targeted literature search for paid amounts directly associated with each CVD event provided the unit costs, which were applied to the projected number of events averted, to calculate costs avoided per member per year (PMPY). One-way sensitivity analyses were performed on events averted, unit costs, and percentages of trial-applicable patients.

Results: Based on three-point MACE events averted, costs avoided PMPY of $6.17 (range: $1.27–$10.94) for CANVAS and $2.75 ($0.19–$4.83) for EMPA-REG were estimated. Costs avoided for individual components of MACE ranged from $0.77 to $3.84 PMPY for CANVAS and from -$0.97 (additional costs) to $1.54 for EMPA-REG. PMPY costs avoided for heart failure were $2.72 for CANVAS and $1.32 for EMPA-REG.

Limitations and conclusions: Models assumed independent, non-recurrent outcomes and were restricted to medical costs directly associated with the trial-reported events. The reductions in CVD events in T2DM patients reported for both CANVAS and EMPA-REG project to a positive cost avoidance for these events in an MCO population. The analysis did not include an assessment of the impact on total cost, as the costs associated with adverse events, drug utilization or other clinical outcomes were not examined.     

The impact of working conditions on sickness absence: a theoretical model and an empirical application to work schedules

This paper explores how poor working conditions impact sickness absence through their effect on health. Our contribution is two-fold. First, we develop a static theoretical model based on the concept of health capital, wherein poor working conditions are partially compensated by higher wages. According to our model, the effect of working conditions on sickness absence is ambiguous. Second, we apply our model to the case of working time arrangements and test the effect of working irregular schedules or work around the clock on sickness absence, using data from the French Labor Force Survey on a specific population (male manual workers in private sector). As heterogeneity may lead to severe bias, we use propensity score matching methods. Our estimates show that working irregular schedules has a significant impact on sickness absence. The results are more mitigated for work around the clock. In any case, the extent crucially depends on age.     

How credible is the North Korean threat?

We perform event analysis on particular episodes of tension in the Korean peninsula between 2000 and 2008, and investigate the effect of the events on South Korean financial markets (stock markets, bond yield spreads and the exchange rate) given that South Korea would be the first affected by a military aggression from North Korea. Surprisingly, in nearly all cases, these events, which have often been dramatized in the world media, have no significant impact on either of these variables or only a very small one. We also find no significant impact of events on listed firms that would a priori be likely to suffer from increased tension between the two Koreas. Since financial markets often contain better predictions than expert opinions or surveys, these results strongly suggest that the North Korean threat is non‐credible.     

A STRUCTURAL RISK‐NEUTRAL MODEL FOR PRICING AND HEDGING POWER DERIVATIVES

We develop a structural risk‐neutral model for energy market modifying along several directions the approach introduced in Aïd et al. In particular, a scarcity function is introduced to allow important deviations of the spot price from the marginal fuel price, producing price spikes. We focus on pricing and hedging electricity derivatives. The hedging instruments are forward contracts on fuels and electricity. The presence of production capacities and electricity demand makes such a market incomplete. We follow a local risk minimization approach to price and hedge energy derivatives. Despite the richness of information included in the spot model, we obtain closed‐form formulae for futures prices and semiexplicit formulae for spread options and European options on electricity forward contracts. An analysis of the electricity price risk premium is provided showing the contribution of demand and capacity to the futures prices. We show that when far from delivery, electricity futures behave like a basket of futures on fuels.     

ON‐THE‐JOB SEARCH,PRODUCTIVITY SHOCKS,AND THE INDIVIDUAL EARNINGS PROCESS*

Individual labor earnings observed in worker panel data have complex, highly persistent dynamics. We investigate the capacity of a structural job search model with on‐the‐job search, wage renegotiation by mutual consent, and i.i.d. productivity shocks to replicate salient properties of these dynamics, such as the covariance structure of earnings, the evolution of individual earnings mean, and variance with the duration of uninterrupted employment, or the distribution of year‐to‐year earnings changes. Structural estimation of our model on a 12‐year panel of highly educated British workers shows that our simple framework produces a dynamic earnings structure that is remarkably consistent with the data.     

Retail network spatial expansion: An application of the percolation theory to hard discounters

This article concerns the spatial organization of a retail network. During the expansion of a retail network, the location decision process does not necessarily lead to a regular distribution of outlets throughout the territory. The case of 5 hard discount store networks in France in their development stage illustrates this situation. A hard discount network strategy to fight against incumbent stores relies on the postulate that its competitiveness stems from its perfect cost control, and consequently, its ability to impose its brands to the consumers. To explain hard discounter spatial strategies, the diffusion theory was primarily developed by retaining only the temporal dimension of the process. But this model is not well established for the disordered environment in which the networks are managed. The percolation theory facilitates a new approach of the diffusion in this disordered medium that represents the retail network.     

Global competition and cooperation in the electronics industry: the case of X-ray equipment, 1900–1970

The electronics industry is often regarded by scholars as an example of a sector driven by endless technological innovation and major competition between a few large companies, thus embodying the common view whereby the free market leads firms to innovate. On the other hand, some business historians have also emphasised that, since the beginning of the twentieth century, most of these companies were engaged in various international cartel agreements. The business and economic history literature on this industry reveals a clear-cut divide between the inter-war years and the post-war era. In this paper, however, we argue that technical and commercial cooperation between large electronics companies continued in various forms despite the spread of anti-trust policies after 1945. In this case study, we explore the global X-ray equipment industry from its beginnings around 1900 to the advent of the CT scanner in the early 1970s. The paper focuses on Siemens and Philips, the two largest manufacturers of radiological equipment. It demonstrates that both companies pursued their commercial and technical cooperation at least until the 1970s, although it was much less overt as during the interwar years.