Generalized R-estimators under conditional heteroscedasticity

In this paper, we extend the classical idea of Rank estimation of parameters from homoscedastic problems to heteroscedastic problems. In particular, we define a class of rank estimators of the parameters associated with the conditional mean function of an autoregressive model through a three-steps procedure and then derive their asymptotic distributions. The class of models considered includes Engel's ARCH model and the threshold heteroscedastic model. The class of estimators includes an extension of Wilcoxon-type rank estimator. The derivation of the asymptotic distributions depends on the uniform approximation of a randomly weighted empirical process by a perturbed empirical process through a very general weight-dependent partitioning argument.     

On the Value Relevance of Retailer Advertising Spending and Same-store Sales Growth

In response to recent calls to study factors that determine a retailer's stock price, this study draws on signaling theory to examine the impact of two key marketing metrics that are widely disclosed by retailers to investors, advertising spending and growth in same-store sales (COMPS), and highlights the moderating role of various firm- and sector-specific factors. Using a stock-response model estimated on a sample of 1,646 observations for 257 retailers, the authors find that the value relevance of advertising spending and COMPS depends on the financial condition of, and the competitive pressures faced by, the retailer. In addition, the positive effect of COMPS on stock returns is found to be stronger in the presence of decreases in advertising spending.     

Optimal certification policy,entry, and investment in the presence of public signals

We explore the optimal disclosure policy of a certification intermediary where (i) the seller decides on entry and investment in product quality, and (ii) the buyers observe an additional public signal on quality. The optimal policy maximizes rent extraction from the seller by trading off incentives for entry and investment. We identify conditions under which full, partial or no disclosure can be optimal. The intermediary's report becomes noisier as the public signal gets more precise, but if the public signal is sufficiently precise, the intermediary resorts to full disclosure. However, the social welfare may reduce when the public signal becomes more informative.     

Product market competition, open shop union and wage

We show that if the product market is not very much concentrated, open shop union, where the union density is less than one, may not be a justification for a positive relationship between product market competition and unionized wage, irrespective of the union density, bargaining power of the union and the union??s preference for wage and employment.     

Managing internationalization and innovation tradeoffs in entrepreneurial firms: Evidence from transition economies

For entrepreneurial firms (EFs), internationalization and innovation present two major avenues for growth. Prior research, based primarily on EFs from advanced economies, demonstrates mixed insights for the relationship between these strategies. A deeper understanding of the tradeoffs involved in the internationalization-innovation relationship may help better comprehend the issue. In this study, we draw on the organizational learning and capabilities-based literatures to examine the relationship in the context of EFs in transition economies (EFTEs). Our findings suggest that in EFTEs, internationalization is negatively associated with the likelihood of innovation. We also find that three knowledge-based capabilities of EFTEs (absorptive capacity, appropriation capability, and managerial capability) positively moderate the aforementioned negative relationship. We do not find any evidence of reverse causality (EFTE innovation impacting internationalization). Our research provides novel insights to the IE literature by shedding light on the internationalization–innovation tradeoffs that EFTEs experience.     

Managing the Impact of a Mutating Global Crisis on Organizations

Atlantic Economic Journal -     

Covariate and Idiosyncratic Shocks and Coping Strategies for Poor and Non-poor Rural Households in India

The objective of the paper is to track the association between different type of shocks experienced by rural households and corresponding coping strategies opted by them as they are, not only exposed to household-level and community level shocks, but also, lack effective risk management strategies which make them vulnerable to get into chronic poverty. A probit analysis has been used to articulate the comparative static distinction of risk management strategies between poor and non poor rural households using Additional Rural Incomes Survey/Rural Economic and Demographic Survey (ARIS/REDS) data surveyed by National Council of Applied Economic Research (NCAER) in rural India across 17 states to get a comparative static analysis. Households, generally, withdraw savings, seek remittances from migrant family members, take loan from formal and informal lenders and sell their existing assets and participate in Government sponsored welfare based programs to control after effect of shocks. Comparatively non-poor rural households could build up safety net (precautionary measure) to cope with price rise and other sudden shocks. But, extremely poor, generally, if don’t get help from relatives or can’t borrow from informal sources, ultimately starve at the time of sudden shocks. The welfare based government programs fail to arrest this extreme situation of grief during the idiosyncratic shocks.

     

Semiparametric binary regression models under shape constraints with an application to Indian schooling data

We consider estimation of the regression function in a semiparametric binary regression model defined through an appropriate link function (with emphasis on the logistic link) using likelihood-ratio based inversion. The dichotomous response variable Δ$\Delta$ is influenced by a set of covariates that can be partitioned as (X,Z)$(X,Z)$ where Z$Z$ (real valued) is the covariate of primary interest and X$X$ (vector valued) denotes a set of control variables. For any fixed X$X$, the conditional probability of the event of interest (Δ=1$\Delta =1$) is assumed to be a non-decreasing function of Z$Z$. The effect of the control variables is captured by a regression parameter β$\beta$. We show that the baseline conditional probability function (corresponding to X=0$X=0$) can be estimated by isotonic regression procedures and develop a likelihood ratio based method for constructing asymptotic confidence intervals for the conditional probability function (the regression function) that avoids the need to estimate nuisance parameters. Interestingly enough, the calibration of the likelihood ratio based confidence sets for the regression function no longer involves the usual χ²${\chi }^2$ quantiles, but those of the distribution of a new random variable that can be characterized as a functional of convex minorants of Brownian motion with quadratic drift. Confidence sets for the regression parameter β$\beta$ can however be constructed using asymptotically χ²${\chi }^2$ likelihood ratio statistics. The finite sample performance of the methods are assessed via a simulation study. The techniques of the paper are applied to data sets on primary school attendance among children belonging to different socio-economic groups in rural India.     

Healthcare resource utilization and costs by age and joint location among osteoarthritis patients in a privately insured population

Aims: To compare healthcare resource utilization and costs between patients aged 18–64 years with osteoarthritis (OA) and matched controls without OA in a privately insured population.

Methods: Patients with OA were selected from de-identified US-based employer claims (Q1:1999–Q3:2011). The index date was defined as the first OA diagnosis indicated by ICD-9-CM codes. One year before and after the index date were defined as the baseline and study periods, respectively. A second OA diagnosis during the study period was also required. Patients with OA were matched one-to-one on age, gender, index date, and minimum length of follow-up to controls without OA. Baseline characteristics and study period resource utilization and costs (2016 USD) were compared between cohorts.

Results: This study identified 199,539 patients with OA (knee: 87,271, hip: 19,953, hand: 15,670, spine: 12,496). The average age was 54 years, and 58% were female. OA patients had higher healthcare resource utilization than matched controls in inpatient, emergency room, and outpatient settings (p?p?Limitations: This sample, obtained using claims data, only includes patients who were actively seeking care for OA and were likely symptomatic. Asymptomatic patients would likely not be captured in this analysis.

Conclusions: Patients with OA incur greater healthcare resource utilization and costs than patients without OA, with substantial variation by joint location.     

On two properties of an unequal probability sampling scheme

Summary For an inclusion probability proportional to size (IPPS) sampling scheme recently proposed by Saxena, Singh and Srivastava (1986), it is shown that under certain simple verifiable conditions (1) the Horvitz-Thompson (1952) estimator based on it has a smaller variance than the variance of the Hansen-Hurwitz (1943) estimator based on probability proportional to size (PPS) sampling with replacement (WR) both involving the same size-measures and the expected sample size in the former being equal to the number of draws in the latter and (2) the Yates-Grundy (1953) estimator for the variance of the Horvitz-Thompson estimator based on this IPPS scheme is uniformly non-negative.