Targeted Undersmoothing

This paper proposes a post-model selection inference procedure, called targeted undersmoothing, designed to construct uniformly valid confidence sets for a broad class of functionals of sparse high-dimensional statistical models. These include dense functionals, which may potentially depend on all elements of an unknown high-dimensional parameter. The proposed confidence sets are based on an initially selected model and two additionally selected models, an upper model and a lower model, which enlarge the initially selected model. We illustrate application of the procedure in two empirical examples. The first example considers estimation of heterogeneous treatment effects using data from the Job Training Partnership Act of 1982, and the second example looks at estimating profitability from a mailing strategy based on estimated heterogeneous treatment effects in a direct mail marketing campaign. We also provide evidence on the finite sample performance of the proposed targeted undersmoothing procedure through a series of simulation experiments

Reconsidering State-Society Relations in South Asia: A Himalayan Case Study

Since the mid-eighteenth century when armies serving the English East India Company (EIC) clashed with the Gorkhali power, British officers depicted Nepal as an example of classical Hindu despotism. Subsequent scholars of the region have not challenged these representations, taking such colonial descriptors as ‘facts.’ The portrayal of the centralized and ‘despotic’ state in South Asian pasts rests upon a certain understanding of the state’s relationship with society. It calls for imagining the Gorkhali regime as alien to the rest of society and supposing that ethnicity and caste are inflexible from one century to the next. The excessive attention given to land systems and revenue extraction to understand the early Gorkhali state formation has equally left us with a limited narrative that is conspicuous for its absence of non-fiscal elements of state making. The frequency and volume of state-society interactions as gleaned from the documents of the period however belie static depiction of power and rule in nineteenth century Nepal. This essay, building on previously unstudied sources, replaces the picture of a static ‘Hindu’despotic state with one that responded to its entanglement with internal and external forces, and put together, piece by piece, a Hindu polity out of a plural society along the Himalayan foothills. The resulting order was processual not a homeostatic structure. Gorkhali rulers succeeded in projecting their power through intertwined strategies of literary and religious patronage, code promulgation, and political manipulation of ritual and rank. The early nineteenth century Gorkhali state like other pre-colonial polities in South Asia was simultaneously coercive and consensual, extractive and re-distributive

Trusting the Trusted: An Empirical Analysis

One aspect of research in the area of bootstrapping of cold start users in trust-aware recommender systems is on guiding new users find trusted users in the trust network. In this paper we examine the question “Which type of users do cold start users actually trust?” We analyze the users trusted by cold start users in the Epinions dataset (Massa & Avesani, 2006a). We examine the set of trusted users on the basis of four critical parameters: number of outgoing links, number of incoming links, number of items rated and a hybrid parameter defined as preference score. We also experimentally evaluate the impact of the four parameters on prediction accuracy. Our analysis shows that cold start users will more likely trust a user with higher number of incoming links as a trusted user even though trusting users with high preference score would result in better prediction accuracy

The Identity Fragmentation Bias

Consumers interact with firms across multiple devices, browsers, and machines; these interactions are often recorded with different identifiers for the same consumer. The failure to correctly match different identities leads to a fragmented view of exposures and behaviors. This paper studies the identity fragmentation bias, referring to the estimation bias resulted from using fragmented data. Using a formal framework, we decompose the contributing factors of the estimation bias caused by data fragmentation and discuss the direction of bias. Contrary to conventional wisdom, this bias cannot be signed or bounded under standard assumptions. Instead, upward biases and sign reversals can occur even in experimental settings. We then compare several corrective measures, and discuss their respective advantages and caveats

E-government Services Adoption and Interdependence: Granger Causality Analysis

Adoption of e-government services varies across the different categories of services: government to citizen services, utility services, commercial services, informational services, social benefit services and mobile based services. Faced with constraint of resources, policy makers devising strategies for better adoption of these services face the challenge of prioritizing among these categories of services. This paper attempts to address this challenge by showing the applicability of Granger causality analysis in studying the causation analysis between the categories of e-government services. We prove the applicability of Granger causality analysis in understanding the independence between e-government service categories by analyzing real transactions data of six categories of e-government services in India. Our analysis shows that the growth of inquiry services in positively impacting the growth of government to citizen transactions is statistically significant. Besides this, both utility services and mobile based services show significant bi-directional Granger causality with government to citizen services. We also discuss policy implications of our analysis

Isometric handgrip strength of agricultural workers from northeast region of India

Handgrip strength is considered as one of the most important factors for performing various agricultural tasks related to torqueing, lifting, pulling, pushing, etc. Hand tools and equipment which are designed based on anthropometric/strength data of different population, may not be suitable for any particular targeted user group. As a result work related musculoskeletal disorders (WMSDs) at upper extremity may occur very often. Lack of strength data of Assamese population (people of Assam, a state in northeast India), motivated present authors to conduct a survey on isometric handgrip strength data of 200 agricultural workers (130 male and 70 female, aged 17-62 years) from the Kamrup district of the state. Maximal isometric handgrip strength was determined using a handheld handgrip dynamometer with standard testing position, protocol and instructions. Descriptive statistics such as mean, standard deviation (SD), percentiles etc. were summarized. Results of student’s t-tests showed significant differences (

Isometric muscular strength data of Indian agricultural workers for equipment design: Critical analysis

Abstract: Human muscular strength is extensively used in Indian agriculture for operating various push-pull type farm tools and equipment.  Incompatibility between operators’ physical capabilities (anthropometric and biomechanical) and demands of physical task to operate tools/equipment often leads to poor performance, low productivity and safety problems.  Although anthropometric data are generally being considered, an inadvertent negligence of using strength database for agricultural tools/equipment design is very common in developing countries like India.  Therefore, in present paper an attempt has been made to statistically analyze available strength data (pooled and regional/state wise data) of male and female Indian agricultural workers to understand nature of variability of those data in terms of difference between pooled Indian data vs. individual state data; difference between male vs. female data across various states of India; and for determining safe operational force limits for handling various agricultural tools/equipment.  Critical evaluation of male and female strength data revealed that there are significant differences (p<0.01 or p<0.05) between mean values of pooled Indian data vs. individual state data for almost all strength variables under study.  It has also been observed that average muscular strength of female is significantly lower (in general 2/3rd of male) than their male counter parts across all states.  Thus, present study concluded that regional variations and gender variation of isometric strength data are crucial ergonomic consideration for using percentile strength data during calculation of operational force limits for designing various agricultural tools/equipment to be used by targeted user populations from various parts of a country like India with huge ethnic diversity.   Keywords: ergonomics, muscular strength, tools and equipment, agricultural workers, Indi