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A public company is a company whose ownership is organized via shares of stock which are intended to be freely traded on a stock exchange or in over-the-counter markets. A public (publicly traded) company can be listed on a stock exchange (listed company), which facilitates the trade of shares, or not (unlisted public company). In some jurisdictions, public companies over a certain size must be listed on an exchange. In most cases, public companies are private enterprises in the private sector, and "public" emphasizes their reporting and trading on the public markets. Public companies are formed within the legal systems of particular states, and therefore have associations and formal designations which are distinct and separate in the polity in which they reside. In the United States, for example, a public company is usually a type of corporation (though a corporation need not be a public company), in the United Kingdom it is usually a public limited company (plc), in France a "socié

IT Investment and its impacts

Shameem Hasan

This thesis empirically explored the impacts of IT investment on three different scenarios under the common denominator / threads of IT investments. It comprises three different essays on the impacts of IT investments. IT investments and its impact on many aspects of the firms are well known - like performance / productivity, output, market value etc. But I looked into areas that were not explored before and examined events that didnât take place after the advent and integration of Information Technology â like the past financial crisis. The main contribution of my dissertation is to examine how IT investments helps in the debt market, how it helps firms fare comparatively better during crisis period and how CEO characteristics influence the well-established existing link between IT investment and Innovation intensity. The first essay examines the effect of IT investment on the cost of bank loan for firms. We argue that IT affects the decision of banks through three mechanisms: wealth effect, risk effect, and information effect. First, IT investment serves as a signal for higher future revenue and lower operational costs, thus greater future cash flows. Second, on one hand, IT may be able to reduce the risk of being locked out to competition or adverse situations; on the other hand, IT investment itself can bring risk to business. Last, the use of IT can lead to better information quality and thus reduce the information asymmetry between firms and banks. Using a sample of 270 firms between the year of 1991 and 2006, we find that IT investment is associated with lower interest rate from banks. More important, we find the strength of this relationship is contingent upon the role of IT in the industry and time period. In my second essay, the goal was to investigate whether IT investment contributed to better or worse performance during the financial crisis of 2007-2009. We took the available data for U.S. public companies (the final sample comprises 570 companies) and traced IT investments made in the years prior to the crisis period, we checked the impact of IT investments on the annual stock returns and relative changes in return (as well as for book values). After controlling for relevant risk and other independent variables during the 2007-2009 periods, we found evidence that indicates that although most of the firms suffered during the crisis period, expenditure in IT was significantly associated with relatively better performance for sample firms during the crisis period. The third essay brings in the role of CEO to examine whether CEOâs characteristics affects the already established link between IT investments and Innovation activities. We constructed data from multiple sources; we also developed empirical model to test our hypothesis and ran a series of regression tests. We find that CEOâs managerial ability and risk-taking incentive (determined by compensation scheme) are complements for IT investment. Thus for CEOs with lower ability and/or lower risk-taking incentive, firms can still achieve higher innovation efficiency by increasing expenditure in IT. On the other hand, CEOâs ownership of the firm substitutes the link. CEO with larger ownership enhances firmâs innovation efficiency by due diligence, but not necessarily through the channel of IT investment. In together, this paper shows that CEO is an important and significant factor in the conversion of IT investment to innovation efficiency.

EPFL2018

The triangular value of patents

Albina Khairullina

This thesis addresses the question of a patent value from three different angles. It comprises three papers on the patent valuation methods. The patent valuation issues are well-known to the world of research and practice. However, the debates over what the patent contributes to the business and the economy overall remain open. The main contribution of my dissertation is that I present novel ways of addressing the value of patents from both micro- and macroeconomic perspectives. I bridge the theoretical modeling with real-world estimations, which sheds light on the legitimacy of certain hypothetical assumptions in patent valuation. In the first paper, I develop a factor model to value patents in a corporate patent portfolio. According to the results, the patent value is determined by five factors, such as forward and backward citations, family size, the number of oppositions received, and the number of claims. I contribute to the literature by introducing an interaction of a quantitative measure of a patent value with its qualitative assessment derived from a survey of patent managers. The results show that model estimates are weakly consistent with an expert opinion on the value of patents. In the second paper, we collaborate with a large multinational company and analyze internal and highly confidential data on product sales, revenues, and other corporate performance measures by tracing each patent down to its product market. To establish causality, we design a randomized controlled trial together with the management of the company, in which some randomly chosen patents are dropped from the portfolio, while others are kept for the duration of the study. To our knowledge, this is the first study that conducts a randomized controlled trial to measure the real market effect of patent protection. In the third paper, we study whether the regulator expands production possibilities of the economy by assigning a standard-essential status to patents. As we show, the innovatorsâ risk of losing the standard-setting game ex-ante attenuates the anticipation of a larger market share. Secondly, since the discovery of new technologies is typically slower than the discounting rate for the monopoly profits, standards with a positive contribution to productivity tend to be growth-reducing. Our results have significant policy implications. Regulators impose Fair, Reasonable, And Non-Discriminatory (FRAND) pricing on standard-essential technologies to compensate for the larger market-share the innovators get. We demonstrate how FRAND regulation of mark-ups has an unambiguously negative effect on growth and long-term growth-destroying consequences.

EPFL2020

The Role of Compromised Accounts in Social Media Manipulation

Tugrulcan Elmas

In recent years we have seen a marked increase in disinformation including as part of a strategy of so-called hybrid warfare. Adversaries not only directly spread misleading content but manipulate social media by employing sophisticated techniques that exploit platform vulnerabilities and avoid detection. It is getting increasingly important to analyze social media manipulation to better understand, detect and defend public dialogue against it.In this thesis, we contribute to the research on social media manipulation by describing and analyzing how adversaries employ compromised social media accounts. We begin by providing a background of social media: we describe the mechanisms and the influence of the platforms to better understand why the adversaries target them. We then give a detailed overview of social media manipulation, and the techniques to detect and counter it. Next, we discuss our contributions in this thesis: 1) an extensive analysis of an attack on social media algorithms using compromised accounts, 2) a study of the implications of compromised bots for bot research through the characterization of retweet bots, 3) a detection method to find compromised accounts that are later repurposed.Firstly, we uncover and analyze a previously unknown, ongoing astroturfing attack on the popularity mechanisms of social media platforms: ephemeral astroturfing attacks. In this attack, a chosen keyword or topic is artificially promoted by coordinated and inauthentic activity to appear popular. Crucially, this activity is removed as part of the attack which facilitates using compromised accounts that are still managed by their original owners. We detected over 19,000 unique fake trends promoted by over 108,000 accounts. Trends astroturfed by these attacks account for at least 20% of the top 10 global trends. We created a Twitter bot to detect the attacks in real-time and inform the public. Secondly, we study the implications of compromised accounts to bot research. We do this by characterizing retweet bots that have been uncovered by purchasing retweets from the black market. We determine that those accounts were compromised as they observe anomalous behavior, or self-state that they are hacked. We then analyze their differences from human-controlled accounts. From our findings on the nature and life-cycle of retweet bots, we point out several inconsistencies between the retweet bots used in this work and bots studied in prior works. Our findings challenge some of the fundamental assumptions related to bots and in particular how to detect them.Thirdly, we define, describe, and provide a detection method for misleading repurposing, in which an adversary changes the identity of a potentially compromised social media accounts via, among other things, changes to the profile attributes in order to use them for a new purpose while retaining their followers. We propose a methodology to flag repurposed accounts, and detected over 100,000 such accounts. We also characterize repurposed accounts and found that they are more likely to be repurposed after a period of inactivity and deleting old tweets. We present a tool to root out accounts that became popular and repurposed later.Our work is significant in presenting how breaches of user security jeopardize platform security and public dialogue. Furthermore, it enhances the knowledge of how the bots and troll accounts work and aid platforms and researchers in building new solutions.

EPFL2022