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2757 items in total found

Working Papers | 2013

Blinded Tests in 2 x 2 Cross-Over Trial

Kaustav Banerjee, Tathagata Bandyopadhyay, and G. Chattopadhyay

We propose tests for equality of treatment effects in the context of a double-blind 2 x 2 cross-over trial which do not require treatment codes to be unblinded and thus can be used as a part of the interim analyses. We first discuss the set-up of a 2 x 2 cross-over trial and state the important assumptions necessary for our procedure. Section 2 discusses implications of blinded interim data analysis under the givensetting and review the test proposed in Millder et al. [27] while pointing out its limitations. Section 3 introduces two preliminary (blinded) tests for equality of means when the data are collected from a 2 x 2 cross-over trial and study their power properties. Section 4 proposes a procedure to improve upon the performance of the tests proposed in Section 3 which require the assumption of equality of variances for the two treatments. The resulting methodology is a two-stage test and is introduced in Section 5. Section 6 discusses the performance of the two-stage test against the benchmark test which would have been effective had the data been unblinded. At the end we add a few concluding remarks.

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Working Papers | 2013

An Expanded Database Structure for a Class of Multi-period, Stochastic Mathematical Programming Models for Process industries

Narain Gupta, Goutam Dutta, and Robert Fourer

We introduce a multiple scenario, multiple period, optimization-based decision support system (DSS) for strategic planning in a process industry. The DSS is based on a two stage stochastic linear program (SLP) with recourse for strategic planning. The model could be used with little or no knowledge of Management Sciences. The model maximizes the expected contribution (to profit), subject to constraints of material balance, facility capacity, facility input, facility output, inventory balance constraints, and additional constraints for non-anticipativity. We describe the database structure for the stochastic linear programming (SLP) based DSS in contrast to the deterministic linear programming (LP) based DSS. In the second part of this paper, we compare a completely relational database structure with a hierarchical one on multiple criteria. We demonstrate that by using completely relational databases, the efficiency of model generation can be improved by 60% in comparison to hierarchical databases.

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Working Papers | 2013

Modeling Situational Factors in Variety Seeking Behaviour: An Extension of the Lightning Bolt Model

Rajesh Nanarpuzha

Variety seeking behavior and its corollary, purchase reinforcement have been looked at from diverse viewpoints in marketing literature. One specific viewpoint has involved looking at the effects of variety seeking behavior on purchase behavior and brand preference. In the area of marketing modeling, variety seeking behavior has been looked at as a consequence of attribute satiation and inherent user preferences. However, the effect of situational variables on variety seeking behavior has often been overlooked. Chintagunta (1999) has made use of the lightning bolt model (Roy, Chintagunta, & Haldar, 1996) to isolate the effects of variety seeking behavior on brand preferences. However, the author has made use of the attribute satiation approach to model variety seeking behavior. In this paper, the attempt has been made to build on the lightning bolt model (Roy et al., 1996) and the variation proposed by Chintagunta (1999) to propose a conceptual model that incorporates the effect of situational variables on variety seeking behavior and thereby, brand preferences. The Indian kirana store and a large-format retail store have been contrasted to set the empirical context for the problem. Alternative methods have been proposed for data collection and for empirically testing the model in this particular context.

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Working Papers | 2013

A Constrained Nash Bargaining Approach to the Stock Rationing Problem in Multi-echelon Supply Chains

Debjit Roy and N. R. Srinivasa Raghavan

In order to survive in the global volatile market place, supply chain analysts' are brainstorming
to arrive at robust inventory control policies that prevents inventory worth of millions
of dollars to get tied up in the chain and at the same time ensures to achieve the differentiated
customer service levels. Inventory rationing is a useful strategy to tackle the above problem
of conflicting objectives, i.e., minimizing inventory costs (holding costs and backorder costs)
and achieving the desired customer service levels. In this paper we consider a multi-echelon
supply distribution system and pose the stock allocation problem in a constrained Nash Bargaining
(NB) setting. The objective of the model is to determine a set of rationing fractions
at the central depot in order to minimize the order-up-to level inventory yet exactly achieving
the differentiated target fill rates. It is our firm belief that the Distribution Resource Planning
(DRP) managers will find the proposed models a useful tool in their stock allocation decision
making process. Rigorous computational experiments suggests that our approach performs
better than the existing ones for this important problem.

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Working Papers | 2013

"Impatience" of Forest Dependent Communities -
Evidence from Andhra Pradesh

B. Sundar and Vineet Virmani

This study is an attempt to generate empirical evidence on the time discount rate or "impatience" of forest dependent communities (FDCs). The FDCs covered in the study include two different geographical regions from the Indian state of Andhra Pradesh-Rayalaseema (a relatively dry forest region with low income) and the coastal region (relatively fertile forest and with higher income). "Impatience" was measured as the revealed individual time discount rate from the choice task methodology. With this measure, on average, members of FDCs from Rayalaseema were found to be more "impatient" compared to their counterparts from the coastal region. Using interval regression, the study also looked at the role of income and socioeconomic variables on their impatience. Incomes of members of FDCs both from Rayalaseema and the coastal region did not contribute to their "impatience". For members of FDCs from Rayalaseema, on average, proximity to urban centers was found to contribute positively to "impatience" and membership to "other backward caste" (relative to "scheduled caste" and "scheduled tribe") negatively so. For members of FDCs from the coastal region, family size and being a shared decision maker within the family contributed negatively to impatience.

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Working Papers | 2013

Attitudes towards Risk of Forest Dependent Communities - Evidence from Andhra Pradesh

B. Sundar and Vineet Virmani

This study is an attempt to generate empirical evidence on attitude towards risk of forest dependent communities (FDCs). The FDCs covered in the study include two different geographical regions from the Indian state of Andhra Pradesh-Rayalaseema (a relatively dry forest region with low income) and the coastal region (relatively fertile forest and with higher income). Attitude towards risk was measured as the revealed degree of risk aversion (as a constant relative risk aversion coefficient) from the multiple price list methodology. With these measures, on average, members of FDCs from Rayalaseema were found to be more risk averse as compared to their counterparts from the coastal region. Using interval regression, the study also looked at the role of income and socioeconomic variables on their risk behaviors. For members of FDCs from Rayalaseema, income was not found to be a contributor towards risk aversion. Including socioeconomic variables in the regression showed that on average being men, married and a shared decision-maker within family contributed positively to risk aversion, and membership to managing committee and having adult children in the family negatively so. Degree of risk aversion for members of FDCs in the coastal region, however, did show a role for income, albeit weak statistically. In particular, members from the low and high income groups were found to be risk seeking and those from the middle income groups risk averse, with family size and education contributing positively to risk aversion and proximity to urban centers negatively so.

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Working Papers | 2013

Market Timing Ability of Indian Firms in Open Market Repurchases

Sobhesh Kumar Agarwalla, Joshy Jacob, and Ellapulli Vasudevan

The paper examines the market timing ability of Indian firms engaged in open market repur-
chases. The study is primarily motivated by the unique disclosure feature of repurchases in
India, where the disclosures are far more frequent than in any other market. We find that
the repurchasing firms in India are able accumulate shares at favorable prices similar to the
US market. However, the cost savings do not translate into significant wealth creation for the
insiders as indicated by the short-run and long-run abnormal returns. This is contrary to the
evidence from markets like the US. Further, the cross-sectional variations in the cost savings
from repurchase execution in India are explained by the overall market returns and not by
firm characteristics. These findings contrast with that of US, where the firm characteristics
significantly explain the cross-sectional variation in the savings measure. It appears that the
more frequent disclosure of repurchase activity in India cripples the market timing ability by
reducing the information asymmetry between the firm and the outsiders. This conclusion is
further supported by the irrelevance of the past or concurrent stock returns in explaining the
time variation in the repurchase activity of firms.

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Working Papers | 2013

Leadership and Creativity in the Indian R&D Laboratories: Examining the Role of Autonomous Motivation, Psychological Capital and Justice Perceptions

Vishal Gupta

The present study investigates the association between R&D-specific leadership approach developed in the Indian context using a combination of qualitative and quantitative data analyses, employee autonomous motivation, psychological capital, fairness perceptions and creativity. Creativity construct was conceptualized as comprising of both behaviors and outcomes. Creative behaviors comprise of idea development (generation and promotion) behaviors and work engagement, while creative performance was measured using quantifiable outputs. Using survey data from 482 scientists in the Indian R&D laboratories, the study found that leader behaviors are directly related to autonomous motivation and justice perceptions that, in turn, are positively related to psychological capital and creative behaviors. Psychological capital is also positively related to creative behaviors. The study found significant positive relationship between work engagement and creative performance. The results of this study provide support for the leadership model and its association with employee perceptual variables, behaviors and objective performance.

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Working Papers | 2013

IIMA in HealthCare Management: Abstract of Publications (2000-2013)

K. V. Ramani

The Indian Institute of Management, Ahmedabad (IIMA), was established in 1961 as an autonomous institution by the Government of India in collaboration with the Government of Gujarat and Indian industry.

IIMA's involvement in the health sector started with the establishment of the Public Systems Group in 1975. In the initial period, our research focused on the management of primary healthcare services and family planning. We expanded our research activities to include the management of secondary healthcare services in the 80s and to tertiary healthcare services in the 90s. Currently our research interests focus on the governance and management issues in the areas on Rural Health, Urban Health, Public Health and Hospital Management.

In June 2004, IIMA Board approved the setting up of a Centre for Management Health Services (CMHS) in recognition of IIMA's contributions to the health sector in the past and the felt need to strengthen the management of health sector in the context of socio-economic developments of our country. The overall objectives of CMHS are to address the managerial challenges in the delivery of health services to respond to the needs of different segments of our population efficiently and effectively, build institutions of excellence in the health sector, and influence health policies and wider environments. All our research projects are externally funded and we have developed research collaborations with 15-20 international universities in USA, UK, Europe, and Asia. CMHS has also established strong linkages with the Ministry of Health and Family Welfare at the national and state government levels, particularly in the states of Gujarat, Maharashtra, Rajasthan, Madhya Pradesh, Chattisgarh, Orissa, and Bihar.

This working paper is a compilation of the abstracts of all our publications in the last 13 years, which includes 3 books, 50 referred journal articles, 66 Working Papers, 6 Chapters in Books and 25 Case Studies.

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Working Papers | 2013

A Framework for Socially Meaningful Evaluations of Technology based Social Innovations

Ankur Sarin and Kavitha Ranganathan

The social innovation space that tries to marry the pursuit of profits and social impact is at interesting cross-roads in developing countries like India. Among other things, the euphoria and subsequent deflation around microfinance, points to the need for a continuous critical examination of not only how well a sector, or organizations within it, are doing on different operational criteria, but also socially locating the evaluative criteria. This implies asking questions of the relevance of metrics being used to evaluate the social problem being targeted, the manner in which the problem is being defined and implications for the relationship between the state and citizens being impacted by private social interventions.
To this end we suggest and test a framework adapted from Fischer (Fischer 1995) that makes a useful distinction between technical verification (performance on indicators relevant to the innovation) and societal validation (relevance of indicators to societal problem being addressed, nature of democratic society promoted etc.) as different levels of evaluation. While most impact reporting standards restrict their scope to technical verification, it is the level of societal validation where most conflicts and controversies lie.
We develop on Fischer's framework in the paper, elaborating on what the different levels of evaluations imply for social enterprises. We elucidate various aspects of the framework with ample examples, drawn from organizations that have garnered attention for their potential to create social impact via the use of technology. Although the scope of the framework is not limited to them, we focus on technology based social innovations in the paper.
We use the framework to both organise the discourse evaluating the impact of the One Laptop per Child project (OLPC), which aims to equip every child in the world with a laptop of his/her own. The purpose of our case study is not to evaluate the OLPC itself, but instead organise the discourse around the impact of OLPC. Therefore, the case study serves to illustrate how the evaluation framework can be used, the manner in which the levels are interrelated, questions that emerge in using the framework and the importance of deliberating on the normative.

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