Change-point analysis through integer-valued autoregressive process with application to some COVID-19 data

In this article, we consider the problem of change-point analysis for the count time series data through an integer-valued autoregressive process of order 1 (INAR(1)) with time-varying covariates. These types of features we observe in many real-life scenarios especially in the COVID-19 data sets, where the number of active cases over time starts falling and then again increases. In order to capture those features, we use Poisson INAR(1) process with a time-varying smoothing covariate. By using such model, we can model both the components in the active cases at time-point t namely, (i) number of nonrecovery cases from the previous time-point and (ii) number of new cases at time-point t. We study some theoretical properties of the proposed model along with forecasting. Some simulation studies are performed to study the effectiveness of the proposed method. Finally, we analyze two COVID-19 data sets and compare our proposed model with another PINAR(1) process which has time-varying covariate but no change-point, to demonstrate the overall performance of our proposed model.     

A Note on the Relationship between Firm Diversification and Corporate Advertising Expenditures

Using data on 200 major U.S. advertisers, our empirical analysis examines the relationship between the degree of firm diversification and corporate advertising expenditures, while controlling for competing explanations. Data on corporate advertising expenditures are obtained from Leading National Advertisers (1989). Compustat line of business data and Hoover's Handbook are used to construct measures of firm diversification, and other firm/industry characteristics included as covariates in our empirical analysis to account for possible alternative explanations. Our results suggest that less diversified firms spend more on corporate advertising.     

Corruption and military spending

Anecdotal evidence relates corruption with high levels of military spending. This paper tests empirically whether such a relationship exists. The empirical analysis is based on data from four different sources for up to 120 countries during 1985–1998. The association between military spending and corruption is investigated by using cross-section and panel regression techniques. The results suggest that corruption is associated with higher military spending as a share of both GDP and total government spending, as well as with arms procurement in relation to GDP and total government spending. The results can be interpreted as evidence that defense spending may be used as a component of an indicator of the quality of governance.     

The role of physical distribution services as determinants of product returns in Internet retailing

Pressure continues to build on Internet retailers to squeeze out inefficiencies from their day-to-day operations. One major source of such inefficiencies is product returns. Indeed, product returns in Internet retailing have been shown to be, on average, as high as 22% of sales. Yet, most retailers accept them as a necessary cost of doing business. This is not surprising since many retailers do not have a clear understanding of the causes of product returns. While it is known that return policies of retailers, along with product attributes, are two important factors related to product return incidents, little is known about which aspects of the online retail transaction make such a purchase more return-prone. In the current study, we seek to address this issue. We use a large data set of customer purchases and returns to identify how process attributes in physical distribution service (PDS) influence product returns. The first attribute involves perceptions of scarcity conditions in inventory availability among consumers when retailers reveal to consumers information on inventory levels for the products that they intend to buy. Our results show that orders in which items are sold when these conditions are revealed to shoppers have a higher likelihood of being returned than orders in which these conditions are not revealed. While prior research has argued that inventory scarcity perceptions have an effect on purchases, our findings suggest that they are also related to the likelihood of these purchases being returned. The second attribute involves the reliability in the delivery of orders to consumers. We find that the likelihood of orders being returned depends on the consistency between retailer promises of timeliness in the delivery of orders and the actual delivery performance of the orders. Moreover, we find that the effect that consistency in the delivery has in the likelihood of returns, is stronger for orders that involve promises for expedited delivery than for orders with less expeditious promises. That is, although the occurrence of returns depends on the delays in the delivery of orders to consumers relative to the initial promises made by the retailers, this effect is more notable for orders that involve promises of fast delivery.     

Mathematical Economics: A Mathematical Approach To Microeconomic Theory

Journal of Quantitative Economics -     

The impact of service quality and marketing on financial performance in the hospital industry: an empirical examination

Service quality and service marketing have both been studied extensively in relation to service organizations. In this paper we examine these areas simultaneously in terms of their impact on financial performance in the hospital industry. Drawing from the literature in the quality and service marketing areas, the area of service quality is represented in terms of the constructs of quality context and quality outcomes. Quality context (QC) describes the environment related to quality practices within a hospital which generally encourages and enhances service quality while quality outcomes (QO) comprises of specific clinical and patient satisfaction outcomes of the hospital. The area of marketing is represented in terms of the constructs of marketing orientation and market/product development outcomes. Market orientation (MO) is a well accepted, albeit complex, construct within the marketing literature. Generally, market orientation can be thought of as the process of effectively collecting, disseminating, and responding to information in order to enhance the marketing function within the hospital. Such information generally relates to market trends, customers, and competitors. Market/product development outcomes (MPD) refer to specific outcomes in relation to product innovation and market segmentation that are general indicators of the marketing effectiveness of the hospital. Although the evidence in the literature suggests that both service quality and marketing are independently related to organizational performance, the precise nature of the relationships among the variables described above is not clearly understood.Based on theoretical considerations, we propose a framework linking the above-mentioned constructs to the financial performance (FP) of an organization. Since QC and MO are theorized to be multidimensional constructs we use the technique of structural equations modeling (SEM) to test the model. Data were collected for the study from hospitals in a five-state region in the US. The results show that the constructs related to both service quality and marketing impact on financial performance. However, the results do not support the proposed framework of relationships. Instead, the results support a sequential chain of relationships among the constructs where MO mediates the effect of QC on QO, and MPD mediates the effect of QO on FP. Implications of these results for the hospital industry as well as for future research in the area are offered.     

Investigating the Cross-Category Effects of Store Brands

Our study examines the cross-category effects of store brand productsin other categories on the products in a target category. Using scannerdata for 13 product categories, we find that higher number of storebrands in other categories increases the store brand share in the targetcategory. In addition, share of the leading national brand in the targetcategory is negatively affected by the number of store brands in othercategories. Our results do not offer evidence for the effects of storebrand promotions in other categories on both the store brand and thenational brands in the target category.     

Challenges of Fiscal Policy in Emerging and Developing Economies

This article presents a systematic analysis of the availability and use of fiscal space in emerging and developing economies. We report two major results. First, emerging and developing economies built fiscal space in the run-up to the Great Recession of 2008–2009, which was then used for stimulus. Since then, fiscal space has shrunk and remains narrow as these economies have taken advantage of historically low interest rates. Second, fiscal policy in emerging and developing economies has become countercyclical (or less procyclical), i.e., “graduated,” since the 1980s, as most clearly demonstrated during the Great Recession. The move towards graduation is most pronounced for those economies with greater fiscal space, which suggests that fiscal space matters for a government’s ability to implement countercyclical fiscal policy.