Performance, Career Dynamics, and Span of Control

There is an extensive theoretical literature based on what is called the scale-of-operations effect, i.e., the idea that the return to managerial ability is higher the more resources the manager influences with his or her decisions. This idea leads to various testable predictions including that higher ability managers should supervise more subordinates, or equivalently, have a larger span of control. And although some of this theory’s predictions have been empirically investigated, there has been little systematic investigation of the theory’s predictions concerning span of control. In this paper we first extend the theoretical literature on the scale-of-operations effect to allow firms’ beliefs concerning a manager’s ability to evolve over the manager’s career, where much of our focus is the determinants of span of control. We then empirically investigate testable predictions from this theoretical analysis using a unique single firm dataset that contains detailed information concerning the reporting relationships at the firm. Our investigation provides strong support both for the model’s predictions concerning wages, wage changes, and probability of promotion, and also for the model’s predictions concerning span of control including predictions derived from the learning component of the model. Overall, our investigation supports the notion that the scale-of-operations effect and additionally learning are important determinants of the internal organization of firms including span of control

Mergers of Equals & Unequals

We examine the organizational dynamics of integration post merger. Our basic question is whether there is evidence of conflict between employees from the two merging firms. Such conflict can arise for several reasons, including firm-specific human capital, corporate culture, power, or favoritism. We examine this issue using a sample of Danish mergers. The results are consistent with the basic hypothesis. Controlling for other effects, employees from the acquirer fare better than employees from the acquired firm, suggesting that they have greater power in the newly merged hierarchy. As a separate effect, the more that either firm dominates the other in terms of number of employees, the better do its employees fare compared to employees from the other firm. This suggests that majority / minority status is also important to assimilation of workers, much as in ethnic conflicts. Finally, greater overlap of operations decreases turnover. This finding is inconsistent with the view that workers of the two firms may be better substitutes for each other. However, the result and our other findings are consistent with the view that more similar workers (in terms of either firm- or industry-specific human capital) are easier to integrate post mergerMergers; internal organization; conflicts; personnel economics

Mergers of equals and unequals

We examine the dynamics of post-merger organizational integration. Our basic question is whether there is evidence of conflict between employees from the two merging firms. Such conflict can arise for several reasons, including firm-specific human capital, corporate culture, power, or favoritism. We examine this issue using a sample of Danish mergers. Controlling for other effects, employees from the acquirer fare better than employees from the acquired firm, suggesting that they have greater power in the newly merged hierarchy. As a separate effect, the more that either firm dominates the other in terms of number of employees, the better do its employees fare compared to employees from the other firm. This suggests that majority / minority status is also important to assimilation of workers, much as in ethnic conflicts. Finally, greater overlap of pre-merger operations decreases turnover. This finding is inconsistent with the view that workers of the two firms substitute for each other, creating efficiencies from merger. However, that result and our other findings are consistent with the view that more similar workers (in terms of either firm- or industry-specific human capital) are easier to integrate post merger

Reply to Rob Smeets’ letter to the editor regarding the article “A comparison of the relationship between depression, perceived disability, and physical performance in persons with chronic pain” (2008)

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90330/1/j.ejpain.2008.08.007.pd

Neural differentiation potential of human bone marrow-derived mesenchymal stromal cells: misleading marker gene expression

Background: In contrast to pluripotent embryonic stem cells, adult stem cells have been considered to be multipotent, being somewhat more restricted in their differentiation capacity and only giving rise to cell types related to their tissue of origin. Several studies, however, have reported that bone marrow-derived mesenchymal stromal cells (MSCs) are capable of transdifferentiating to neural cell types, effectively crossing normal lineage restriction boundaries. Such reports have been based on the detection of neural-related proteins by the differentiated MSCs. In order to assess the potential of human adult MSCs to undergo true differentiation to a neural lineage and to determine the degree of homogeneity between donor samples, we have used RT-PCR and immunocytochemistry to investigate the basal expression of a range of neural related mRNAs and proteins in populations of non-differentiated MSCs obtained from 4 donors. Results: The expression analysis revealed that several of the commonly used marker genes from other studies like nestin, Enolase2 and microtubule associated protein 1b (MAP1b) are already expressed by undifferentiated human MSCs. Furthermore, mRNA for some of the neural-related transcription factors, e.g. Engrailed-1 and Nurr1 were also strongly expressed. However, several other neural-related mRNAs (e.g. DRD2, enolase2, NFL and MBP) could be identified, but not in all donor samples. Similarly, synaptic vesicle-related mRNA, STX1A could only be detected in 2 of the 4 undifferentiated donor hMSC samples. More significantly, each donor sample revealed a unique expression pattern, demonstrating a significant variation of marker expression. Conclusion: The present study highlights the existence of an inter-donor variability of expression of neuralrelated markers in human MSC samples that has not previously been described. This donor-related heterogeneity might influence the reproducibility of transdifferentiation protocols as well as contributing to the ongoing controversy about differentiation capacities of MSCs. Therefore, further studies need to consider the differences between donor samples prior to any treatment as well as the possibility of harvesting donor cells that may be inappropriate for transplantation strategies

Elevated activity of the sympathetic nervous system is related to diminished practice effects in memory:A pilot study

BACKGROUND: Reductions in memory practice effects have gained interest as risk factor for future cognitive decline. Practice effects vary with age and can be moderated by factors such as individual variability in arousal or stress experience acting as an additional cognitive load. OBJECTIVE: In the current pilot study, we examined whether sympathetic nervous system activation moderates the relationship between age and practice effects. METHODS: Thirty cognitively healthy individuals aged 40–70 years performed a mnemonic discrimination task twice. Salivary alpha amylase (sAA) samples were obtained at different time points as a proxy of sympathetic activity. Spearman correlations examined the relation between practice effects and sAA. Subsequently, age by sAA interactions on practice scores were explored with bootstrapped linear regression models. Additionally, participants were divided in learners (exhibiting practice effects) and non-learners based on the difference in mnemonic discrimination performance. RESULTS: Higher age and baseline SNS activity were independently related to lower practice effects. The non-learners showed significantly higher sAA scores at all time points compared to learners. Among the learners, baseline-adjusted lower levels of sAA after encoding were associated with greater practice effects, particularly in middle-aged individuals. No such interaction was observed for non-learners. CONCLUSION: These results show that higher baseline sympathetic activation is associated with worse practice effects independently of age. Additionally, in a subgroup of middle-aged learners practice effects were observed when sympathetic activity remained low during learning. These findings suggest that elevated sympathetic nervous system activation may be a promising indicator of imminent cognitive decline