Estimating Causal Installed-Base Effects: A Bias-Correction Approach

New empirical models of consumer demand that incorporate social preferences, observational learning, word-of-mouth or network effects have the feature that the adoption of others in the reference group - the “installed-base” - has a causal effect on current adoption behavior. Estimation of such causal installed-base effects is challenging due to the potential for spurious correlation between the adoption of agents, arising from endogenous assortive matching into social groups (or homophily) and from the existence of unobservables across agents that are correlated. In the absence of experimental variation, the preferred solution is to control for these using a rich specification of fixed-effects, which is feasible with panel data. We show that fixedeffects estimators of this sort are inconsistent in the presence of installed-base effects; in our simulations, random-effects specifications perform even worse. Our analysis reveals the tension faced by the applied empiricist in this area: a rich control for unobservables increases the credibility of the reported causal effects, but the incorporation of these controls introduces biases of a new kind in this class of models. We present two solutions: an instrumental variable approach, and a new bias-correction approach, both of which deliver consistent estimates of causal installed-base effects. The bias-correction approach is tractable in this context because we are able to exploit the structure of the problem to solve analytically for the asymptotic bias of the installed-base estimator, and to incorporate it into the estimation routine. Our approach has implications for the measurement of social effects using non-experimental data, and for measuring marketing-mix effects in the presence of state-dependence in demand, more generally. Our empirical application to the adoption of the Toyota Prius Hybrid in California reveals evidence for social influence in diffusion, and demonstrates the importance of incorporating proper controls for the biases we identify

Peer grading reduces instructor’s workload without jeopardizing student learning in an undergraduate programming class

In an undergraduate programming class taught at Nanyang Technological University, Singapore, students (N=243) were given an opportunity to grade reports submitted by their peers. 10% of all students participated in peer grading and were satisfied with the grade given to them by peers (i.e., this group did not use instructors’ resources). 13% participated in peer grading, updated their reports based on peer feedback, and submitted to a course tutor for final grading. We have shown that even though students who participated in peer grading and updated their reports achieved higher scores, but it happened because they were stronger students to begin with. At the same time, scores of students who participated in peer grading and did not re-submit their reports to an instructor were not lower than average scores. Thus peer grading can be recommended in teaching programming classes as a strategy that reduces instructors’ workload while not jeopardizing students’ learning

Review Study on Fintech A Topic of Cyber Security

Fintech, a portmanteau of "financial technology", refers to firms using new technology to compete with traditional financial methods in the delivery of financial services. Artificial intelligence, Blockchain, Cloud computing, and big data are regarded as the "ABCD" (four key areas) of FinTech. The use of smartphones for mobile banking, investing, borrowing services, and cryptocurrency are examples of technologies designed to make financial services more accessible to the general public. Financial technology companies consist of both startups and established financial institutions and technology companies trying to replace or enhance the usage of financial services provided by existing financial companies. A subset of fintech companies that focus on the insurance industry are collectively known as insurtech or insuretech companies

Digital Transformation of Education for Quality Sustainability-Reference Based

Digital transformation (DX) is the adoption of digital technology by an organization to digitize non-digital products, services or operations. The goal for its implementation is to increase value through innovation, invention, customer experience or efficiency. Digital transformation entails considering how products, processes and organizations can be changed through the use of new, digital technologies. Digital transformation can be seen as a socio-technical programme

The Multiset Partition Algebra

We introduce the multiset partition algebra $\mathcal{MP}_k(\xi)$ over $F[\xi]$, where $F$ is a field of characteristic $0$ and $k$ is a positive integer. When $\xi$ is specialized to a positive integer $n$, we establish the Schur-Weyl duality between the actions of resulting algebra $\mathcal{MP}_k(n)$ and the symmetric group $S_n$ on $\text{Sym}^k(F^n)$. The construction of $\mathcal{MP}_k(\xi)$ generalizes to any vector $\lambda$ of non-negative integers yielding the algebra $\mathcal{MP}_{\lambda}(\xi)$ over $F[\xi]$ so that there is Schur-Weyl duality between the actions of $\mathcal{MP}_{\lambda}(n)$ and $S_n$ on $\text{Sym}^{\lambda}(F^n)$. We find the generating function for the multiplicity of each irreducible representation of $S_n$ in $\text{Sym}^\lambda(F^n)$, as $\lambda$ varies, in terms of a plethysm of Schur functions. As consequences we obtain an indexing set for the irreducible representations of $\mathcal{MP}_k(n)$, and the generating function for the multiplicity of an irreducible polynomial representation of $GL_n(F)$ when restricted to $S_n$. We show that $\mathcal{MP}_\lambda(\xi)$ embeds inside the partition algebra $\mathcal{P}_{|\lambda|}(\xi)$. Using this embedding, over $F$, we prove that $\mathcal{MP}_{\lambda}(\xi)$ is a cellular algebra, and $\mathcal{MP}_{\lambda}(\xi)$ is semisimple when $\xi$ is not an integer or $\xi$ is an integer such that $\xi\geq 2|\lambda|-1$. We give an insertion algorithm based on Robinson-Schensted-Knuth correspondence realizing the decomposition of $\mathcal{MP}_{\lambda}(n)$ as $\mathcal{MP}_{\lambda}(n)\times \mathcal{MP}_{\lambda}(n)$-module.Comment: Revised version based on a referee's repor

Formal methods for reuse of design patterns and micro-architectures

Software reuse is recognized to have the potential for improved productivity of quality software. Class reuse, micro-architecture reuse, and reuse of application frameworks are the three distinct levels of software reuse. This thesis examines the critical issues in providing support for different levels of reuse through formal specifications of reusable components. The formal specification language Larch/C++ has been used in reuse research projects and has been found to be adequate for specifying the behavior of class interfaces. We strengthen this claim by applying this methodology to several classes chosen from Rogue Wave library. We then provide extensions to the language for specifying object collaborations in a micro-architecture. We then illustrate this specification methodology for a micro-architecture chosen from a design pattern repository. In this context, we have also discussed the need to formally document design patterns and provided a formal framework within which design patterns can be formalized. Finally, we present the conceptual schema for a design pattern repository and discuss the query language features for storage and retrieval of design patterns

Estimating Potential Operational Cost Savings by Migrating On-Premises to Cloud: A Study using Amazon TCO

In order to use Amazon TCO(Total cost of ownership) calculator to compute the company operational cost saving by migrating on-premises, Colocation workloads to the AWS cloud, we started investigating the case studies showing on the AWS web page. Cases are categories by either company type or by solution. Data are gathered from Amazon webpage. The following reports are from TCO calculator to show the IT cost savings based on both qualitative and quantitative methods. By solution, the parameters like Big Data, Data Center Migration, Enterprise Solutions, Financial Services, Healthcare & Life Sciences, Internet of Things, Machine Learning & Artificial Intelligence and Web & Mobile Apps are normally considered. By company the parameters like type and size, Enterprises, Startup and Public Sector are considered

Expansion into India and Developing A Business Strategy

Globalisation is the new buzzword that has come to dominate the world. Several reasons can be attributed to these changes. One of the reasons is globalization, the explosive growth of global trade, International competition and the other is technological change. Market success goes to those companies best matched to the current environmental imperatives. This process is having significant impacts on India and China, two highly populated countries in the world; exemplify the striking similarities and vast differences that characterize the Asian region. Once considered difficult markets to enter, Emerging market powerhouses such as China and India are leading the way with one third of the world population and an annual GDP growth rate in the 6% to 8% range. Here we examine the environmental factors and the competitive advantage of India, followed by determining the various modes of entry and finally the cultural and business practices in the economy. India presents a vast potential for overseas investment and is actively encouraging the entrance of foreign players into the market. No company of any size, aspiring to be a global player can for long ignores this country. Keywords: India, Competitive advantage, Strategy, Culture & Environmen

Engine-driven synchronous generators: design considerations for grid code compliance

This thesis aims to provide a set of design criteria for designing synchronous generators (SGs) for engine driven generating sets to meet the emerging grid code requirements. Historically, central plants have been an integral part of the electric grid, in which the power generation facilities are typically located closer to the resources or further away from the loads. Liberalization of the energy market in the early parts of the 21st century combined with stringent environmental policies and emission regulation have forced electrical energy providers to opt for renewable sources and distributed generation. While both these methods of power generation offer better efficiency and economies of scale compared to large power plants, they introduce instability in the grid. To ensure stable supply of electrical power to consumers, many transmission and distribution system operators are enforcing performance expectations on power plants connected to the grid – Grid Codes. These regulations pose great design challenges to the manufacturers and designers of generating sets and associated components, especially synchronous generator (SG) manufacturers. In this work, relevant grid codes are analyzed and specific requirements are defined. A practical and quick analysis method is developed and then used to simulate engine driven SGs connected to electric grid. A neural network based simplification is applied to minimize the number of simulations required to provide guidelines for designing SGs for grid code compliance. Low Voltage Ride Through tests are performed to validate the proposed guidelines. The effects of system solutions on the design parameters are also briefly analyzed. The proposed design criteria are applied to SGs and are validated through grid code certification tests. As vessel to prove the validity of the concepts mentioned above, a 1400 KVA alternator is prototyped and experimental measurements are finally performed. The work presented in the thesis has led to a comprehensive understanding of grid codes and their effect on design and selection of engine driven SGs is obtained and a granted patent on a novel retrofit-able method to reduce fault currents in a SG