Economic Factors Underlying the Unbundling of Advertising Agency Services

This paper addresses a longstanding puzzle involving the unbundling of services that has occurred over more than two decades in the U.S. advertising agency industry: How can the shift from the bundling to the unbundling of services be explained and what accounts for the slow pace of change? Using a cost-based theoretical framework of bundling due to Evans and Salinger (2005, 2008), we develop a simple model of an advertising agency's decision to unbundle its services as a tradeoff between the fixed cost to the advertiser of establishing and maintaining a relationship with an advertising agency and pecuniary economies of scale available in providing media services. The results from an econometric analysis of cross-sectional and pooled data collected by the U.S. Census Bureau for quinquennial censuses conducted between 1982 and 2002 support the key predictions of the model. We find that advertising agency establishments are more likely to unbundle if they are large and diversified in their service offerings and are less likely to do so with increasing age and greater geographical scope. We also find a strong trend toward unbundling over time, a result that is partially explained by increases in media prices over time.

The Effects of Macular Photocoagulation on Visual Field

Purpose: To evaluate visual field and nerve fiber layer thickness changes after Macular photocoagulation for treatment of diabetic macular edema. Setting: Rassoul Akram Hospital, Tehran, Iran. Material and method: Twenty six eyes with history of diabetes and clinically significant macular edema candidate for Macular photocoagulation were included in this prospective interventional case series. All patients underwent 10-2 and 24-2 Humphrey Visual Field Test with Swedish Interactive Thresholding Algorithm (SITA) standard strategy and also optic nerve and macular optical coherence tomography (OCT), before and 6 months after macular laser photocoagulation. Then visual field, peripapillary and macular nerve fiber layer thickness of each eye were compared before and after photocoagulation. Results: The mean age of patients was 57.60 ± 8.99 (range 33-73) years. There was no statistically significant change after photocoagulation compared to before the procedure regarding the mean deviation, pattern standard deviation and foveal threshold in visual field 10-2 and 24-2 tests except for pattern standard deviation in 10-2 test. Conclusion: Based on our results it seems that visual field is not affected by macular laser photocoagulation

Prevalence of diabetic peripheral neuropathy in Iran : A systematic review and meta-analysis

Peer reviewedPublisher PD

Bushehr Elderly Health (BEH) programme: study protocol and design of musculoskeletal system and cognitive function (stage II).

Abstract INTRODUCTION: Musculoskeletal disorders and cognitive diseases are prevalent, and they are significant determinants of morbidity and mortality in older adults. The aim of this study is to investigate the prevalence of musculoskeletal and cognitive diseases and their risk factors and also to assess their associations during future follow-ups. METHODS AND ANALYSIS: Bushehr Elderly Health (BEH) programme is a population-based prospective cohort study being conducted in Bushehr, a southern province of Iran. A total of 3000 older people aged ≥60 years participated in the first stage from which 2772 were eligible to participate in the second stage, which started after 2.5 years. Data including demographic status, lifestyle factors, general healthandmedical history, and mentalandfunctional health are collected through a questionnaire. Anthropometric measures, performance testsandmuscle strength, blood pressure and and body composition measurements are done. A total 25 cc venous blood is taken, and sera are stored at -80°C for possible future analyses. ETHICS AND DISSEMINATION: The study protocol was approved by the ethics committee of Endocrinology and Metabolism Research Institute, affiliated to Tehran University of Medical Science as well as the Research Ethics Committee of Bushehr University of Medical Sciences. A written informed consent was signed by all the participants. The study findings will show the prevalence of musculoskeletal disease, cognitive impairment and their risk factors in an elderly population. The participants will be followed during the study to measure the occurrence outcomes.This study will also have the potential to inform the development of beneficial interventions to improve the management of musculoskeletal and cognitive impairment in Iran and other countries in the Middle East.Our findings will be disseminated via scientific publication as well as presentation to stakeholders, including the patients, clinicians, the public and policymakers, via appropriate avenue

Quality Sorting and Networking: Evidence from the Advertising Agency Industry

This paper provides a model of knowledge sharing and networking among single unit advertising agencies and investigates the implications of this model in the presence of heterogeneity in agencies’ quality. In a stylized screening model, we show that, under a modest set of assumptions, the separation outcome is a Pareto-undominated Nash equilibrium. That is, high quality agencies locate themselves in a high wage and rent area to sift out low quality agencies and guarantee their network quality. We identify a necessary condition for the separating equilibrium to exist and to reject the pooling equilibrium even in the presence of agglomeration economies from networking. We derive the maximum profit of an agency and show the condition has a directly testable implication in the empirical specification of the agency’s profit function. We use a sample of movers—existing agencies that relocate among urban areas—in order to extract a predetermined measure of their quality prior to relocation. We estimate the parameters of the profit function, using the Census confidential establishment-level data, and show that the necessary condition for separation is met and that there is strong separation and sorting on quality among agencies in their location decisions.Advertising, Agglomeration, Industrial Concentration, Business Services, Discrete Choice, Knowledge Spillovers, Learning, Location Decision, Poisson Regression, Nested Logit, Screening, Separating Equilibrium, Sorting

RETRACTED: Facies analysis and depositional environments of the Oligocene–Miocene Asmari Formation, Zagros Basin, Iran

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. The article duplicates significant parts of three other articles without proper citations (Allahkarampour Dill, M., Seyrafian, A., Vaziri-Moghaddam, H., 2010. The Asmari Formation, north of the Gascharan (Dill anticline), southwest Iran: facies analysis, depositional environments and sequence stratigraphy, Carbonates Evaporites, 25, 145-160, http://dx.doi.org/10.1007/s13146-010-0021-6; Jamalian, M., Adabi, M.H., Moussavi, M.R., Sadeghi, A., Baghbani, D., Ariyafar, B., 2011. Facies characteristic and plaoenvironmental reconstruction of the Faliyan Formation, Lower Cretaceous, in the Kuh-e Siah area, Zagros basin, southern Iran. Facies 57, 101-122, http://dx.doi.org/10.1007/s10347-010-0231-3; Bahrami, M., Sahraeyan, M., Taherkhani, K., 2012, Microfacies and Sedimentary envrionments of Dalan Formation at Surmeh Mountain, Folded Zagros Zone, Southwestern Iran. International Journal of Basic and Applied Sciences 4, 380-389, http://dx.doi.org/10.14419/ijbas.v1i4.251). The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process

Did the COVID-19 pandemic permanently impact e-commerce in the US market?

The pandemic compelled many individuals, initially hesitant about online shopping, to overcome their reservations, acquire essential skills, and transition to online retail. This provided a natural experiment to assess whether the barriers to online shopping and the comfort of traditional in-store habits have hindered a broader shift to e-commerce. This paper uses the US retail data to analyze e-commerce activities before, during, and after the pandemic to determine whether the pandemic has permanently altered the pattern of the activities to determine whether the pandemic has permanently altered the pattern of the activities by utilizing structural break detection tools. Additionally, we carry out a forecasting exercise for post-pandemic based on pre-pandemic data to confirm our findings. Results suggest that while e-commerce activities surged during lockdown, they have predominantly reverted to pre-pandemic patterns. Our findings caution both investors and companies against overreaction in the face of exuberant changes in the market to avoid painful corrections afterward