It is argued that a Bitcoin-style money-like informational commodity may constitute an effective instrument for the further development of Islamic Finance. The argument involves the following elements: (i) an application of circulation theory to Bitcoin with the objective to establish the implausibility of interest payment in connection with Bitcoin, (ii) viewing a Bitcoin-like system as a money-like exclusively informational commodity with the implication that such a system need not support debt, (iii) the idea that Islamic Finance imposes different requirements compared to conventional financial policies on a money concerning its use as a tool for achieving social and economic objectives, and (iv) identification of two aspects of mining, gambling and lack of trust, that may both be considered problematic from the perspective of compliance with the rules of Islamic Finance and a corresponding proposal to modify the architecture of mining in order to improve compliance with these rules.
White House Conferences on Aging, held roughly every 10 years since 1961, have “generated ideas and momentum prompting the establishment of and/or key improvements in … programs that represent America’s commitment to older Americans” (The White House, 2015a). In terms of economic security, notably, the 1961 conference gave a push to the enactment of Medicare by recommending the provision of medical care for the aged through Social Security (Senate Special Committee on Aging, 1961). In 1971, President Nixon advocated inflation-proofing Social Security benefits, saying “It does not make sense to have … benefits constantly behind inflation” (Nixon, 1971), language backed-up when he signed the 1972 amendments to the Social Security Act implementing automatic cost of living adjustments (the “COLA”). While unlikely that this year’s conference will see the fruits of its labor enacted into sweeping policy change in the near term, it could play an important agenda-setting role for future congresses and presidents if conference planners and delegates: Explicitly reject the “entitlement crisis frame” and language; Advance the intergenerational understanding of Social Security; Highlight economic insecurity among today’s seniors Sound the alarm on the looming retirement income crisis; Consider benefit increases in Social Security as a critical option Once a neutral budget term, “entitlement” has taken on new meaning in policy, media and even everyday discourse—one that diminishes the dignity of the old and contributes to the mis-framing of policy discussions about the economic consequences of the aging of America. Conference planners and participants should reject “entitlements” language and urge politicians and the press to do likewise. Here’s why. Americans properly understand Social Security and Medicare as benefits they have earned through lifelong contributions from their (or a family member’s) earnings, not as a “hand-out.” Medicaid, in turn, ensures that the poor as well as many very sick Americans obtain needed health care. Subtle or not, “entitlement” terminology implies that somehow such benefit protections are not deserved. Intended or not, the language chips away at the self-esteem and reinforces negative stereotypes that somehow the old—like spoiled, overly entitled children or adults—are demanding and taking more than they deserve (Altman & Kingson, 2015). The terminology of entitlement is functional for those wanting to scale-back or otherwise radically change—Social Security, Medicare, and Medicaid. Rather than frontally attacking these popular programs, it allows them to obfuscate their intentions by attacking “entitlements.” Lumping these programs together as a “unified entitlement problem” provides a convenient frame for advancing and reinforcing the claim that entitlement spending is the largest cause of federal deficits and the national debt, and that left unchecked this spending will bankrupt the nation. As William Greider writes in The Nation, the political consequences of this shift in meaning are not benign: For many years, the smug elites of Wall Street have peddled “entitlement reform” as a sly euphemism for cutting Social Security. And Washington’s political elites, including President Obama, bought into the propaganda. Social Security, not to mention Medicare and Medicaid, was driving the nation into ruinous debt if government did not act to curb this venerable New Deal program. Think tanks and editorial writers, political reporters and TV talkers, witlessly embraced the big lie and promoted it as indisputable truth (Greider, 2014). Equally problematic, the terminology of “entitlement,” “entitlement problem,” and “entitlement crisis” distracts attention from tax spending sprees (e.g., profligate tax cuts and expenditures primarily benefitting well-off constituencies), two wars paid for with credit cards, financial mismanagement leading to the near collapse of our economy, and widening inequalities of income and wealth. Whatever the problem, this frame offers cuts to spending on Social Security, Medicare, and Medicaid as solution. At any one point in time Social Security serves all age groups and, over time, all generations. Princeton economist J. Douglas Brown, an architect of the Social Security Act, spoke eloquently of Social Security as a covenant reaching across generations and arising from a commitment to mutual responsibility that undergirds civilization. This covenant “underlies the fundamental obligation of the government and citizens of one time and the government and citizens of another time to maintain a contributory social insurance system” (Brown, 1977, 31–32). The most important source of income for retirees, Social Security is also working American’s most reliable disability insurance and the nation’s largest children’s program. Indeed, 3.4 million dependent young children and one million dependent adults disabled before age 22 receive benefits each month. The most significant source of income flowing into the homes of 7.4 million children being raised by grandparents or other older relatives, Social Security is also the most important life and disability insurance working parents have, protecting nearly all of the nation’s 74 million children. As important as Social Security is for today’s old, it is likely to be even more so for today’s young- and middle-aged workers. Indeed, it is they who have more at stake if benefits are cut or expanded (Altman & Kingson, 2015). Unfortunately, in policy discourse Social Security is often presented—by both friends and foes—as if it is only a program for the old. And, the prime sponsor of this year’s WHCOA contributes to this mischaracterization. The President’s 2007–2008 presidential primaries and general election campaigns and the White House website provide case in point. Unionists, women, religious groups, environmentalist, and the like were listed among the 25 or so groups providing special support for candidate Obama (e.g., “_____ for Obama”). “Seniors for Obama” was nowhere to be found on this list. Instead, seniors were assigned to the “Issues” section of the website under “Seniors and Social Security.” The problem here is that “Seniors” are not issues, and, “Social Security” benefits and policy concerns everyone, not just seniors. A one-time occurrence would be of little concern. But in spite of requests by supporters engaged in the campaign and followed by similar requests at White House meetings, “Seniors” and “Social Security” remain joined under the “Issues” tab on The White House (2015b) website (see Figure 1). Seniors are not issues. Like the contemporary use of the word “entitlement,” intended or not, defining seniors as “an issue” is, at best, inaccurate, and, at worst, disrespectful. And presenting Social Security narrowly as an issue primarily of concern to the old misframes policy discussions. So, it is time for the White House to push the “reset” button… Language frames issues and conveys attitudes. Like the contemporary use of the word “entitlement,” intended or not, defining seniors as “an issue” is, at best, inaccurate, and, at worst, disrespectful. And presenting Social Security narrowly as an issue primarily of concern to the old misframes policy discussions. So, it is time for the White House to push the “reset” button with regard to how it talks about older Americans and Social Security. Failing this, the WHCOA delegates could perform an important service by raising such concerns. By virtually any measure, the economic status of the old has, on average, improved since the 1950s, with, for example, poverty rates declining under the official poverty measure from roughly 35% in 1959 to 9% today (15% when the Census Bureau’s new Supplemental Poverty measure is used). But contrary to stereotypes, most seniors are not living on easy street. A small percentage is wealthy, while many more live in poverty or near the margin of economic insufficiency. Indeed 48% of seniors are economically vulnerable when 200% of the New Supplemental Poverty Measure is used as the standard. Others—including many among the one out of four senior households with annual incomes in excess of $50,000—are comfortable but often only one shock away from serious financial problems (Altman & Kingson, 2015). Monthly Social Security benefits for seniors are modest, averaging just $1,328 in January 2015. Yet, two thirds of beneficiaries, 65 and over, receive at least half of their income from Social Security (U.S. Social Security Administration, 2014). While the struggle to make ends meet is a burden many seniors face, this pattern of economic stress is generally more pronounced among particular demographic groups—notably Latinos, African Americans, unmarried women, and the oldest old—who are very much at risk for living in poverty based on their limited access to resources and societal limitations that have prevented many from accumulating wealth over their lifetimes. Also, a large numbers of older workers, with health limitations and/or little opportunity to work, accept Social Security retired worker benefits at early ages (e.g., 62), thus sustaining large, permanent reductions in their monthly benefits. Social Security has helped maintain a standard of living for many families of color in America that may otherwise not be possible. People of color rely more heavily on survivor and disability benefits, reflecting lower educational attainment and higher incidence of poverty and morbidity (Martin, 2007). While non-Hispanic whites are more likely to possess wealth outside of their Social Security retirement benefits, many people of color rely solely on what they earned from Social Security for financial stability (Rockeymoore & Lui, 2011). Many people of color have also been unable to obtain wealth through their lifetimes due to past racial discrimination in American policies, yielding a disproportionate reliance on Social Security benefits to ensure that they are able to meet basic monthly expenses. While acknowledging the heterogeneity of economic circumstance among today’s old, the 2015 WHCOA provides opportunity to highlight the very real financial insecurities facing the majority of seniors today, especially those who are most vulnerable. American workers face a looming retirement income crisis, where far too many will find themselves unable to maintain their standards of living when they grow old. Allianz Life Insurance Company reported, from its 2010 survey of 3,257 people, that “an overwhelming 92%” answered that they absolutely (44%) or somewhat (48%) believe that the nation faces a retirement income crisis, with “more than half (54%)” of persons ages 44–49 saying they are “totally unprepared” for retirement (Allianz Life Insurance Company, 2010). In their 2013 retirement confidence survey, the Employee Benefit Research Institute found that only “13 percent are very confident they will have enough money to live comfortably in retirement,” the lowest ever reported in the 23 years of conducting this annual survey. This lack of confidence is not surprising as the past 35 years have not been good to most American workers. Only the top 10% of the income distribution have seen aggregate gains in household income (Picketty, 2014). From 1979 until the eve of the Great Recession in 2007, almost two fifths of all gains in household income were received by the top 1% (Hacker & Pierson, 2010), while men in the bottom 60% saw their real wages decline (Economic Policy Institute, 2012). Further, traditional private sector defined benefits are rapidly disappearing, public sector plans under political attack, and 401K and related retirement vehicles primarily benefit the well-off. And changes enacted in the 1983 (e.g., raising retirement ages, taxing benefits) have reduced benefits by roughly 24% for persons born after 1959 (Altman & Kingson, 2015). The economic crash furthered the deterioration of retirement prospects for countless individuals. Since 2008, many people in their 40s and 50s have been balancing substantial losses of 401(k), IRA and other savings, pension protection, housing equity, and job security with the rising cost of health care and college tuitions. The median income of households headed by persons 55–64 dropped from $61,700 in 2009 to $58,626 in 2012 (Kingson, 2013). Post-crash in 2013—after the stock market increased and housing prices improved—52% of households were on a glide path to an inadequate retirement income (Munnell, Hou, & Webb, 2014), presumably as much as two thirds more if health and long-term-care costs were included in this risk assessment (Altman & Kingson, 2015). According to the Pension Rights Center there is a $6.6 trillion deficit between what Americans have saved for retirement and what they should have saved in order to maintain their current standard of living. According to the National Institute on Retirement Security 38.3 million working-age households (45%) do not have any retirement account assets (National Institute on Retirement Security, 2013). Even among working households with retirement savings, “Four out of five working households have … less than one times their annual income” (National Institute on Retirement Security, 2013, 11). Thus, the WHCOA has an important opportunity to sound the alarm on the retirement income crisis. … the WHCOA has an important opportunity to sound the alarm on the retirement income crisis. Responding to the looming retirement income crisis of today’s workforce and tenuous economic circumstances of many among today’s retirees, legislative proposals are being advanced which increase Social Security’s modest, though vital, protections while simultaneously strengthening program financing. These proposals include revenue measures such as lifting the payroll contribution ceiling, gradually increasing the contribution rate over 20 years, and diversifying trust fund investments. With respect to today’s and tomorrow’s retirees, on the benefit side, they include such proposals as modest across the board increase in benefits, larger minimum benefit payments for low wage-workers, caregiver credits, and use of the Consumer Price Index for the Elderly (CPI-E) to calculate COLAs. A poll by the National Academy of Social Insurance (NASI) indicates that our Social Security system is supported across all political groups; self-reported Democrats, Republicans, and Tea-Partiers alike agree that Social Security benefits should be expanded because they understand the importance of the system to their families and communities (Tucker, Reno, & Bethell, 2013). Americans favor having millionaires and billionaires pay the same rate by raising the payroll contribution cap, currently set at $118,500 for 2015 (U.S. Social Security Administration, 2015). Of course, many disagree with the proposition that it is time to expand Social Security, but that should not stop the WHCOA from recommending that very serious consideration be given to such proposals. Whatever the outcome, the nation will benefit from a full and open debate and the WHCOA can serve as vehicle to facilitate such debate. The 2015 White House Conference on Aging has the opportunity to delve into diverse issues affecting older Americans, their families, and caregivers. As 2015 begins, we look forward to the 80th Anniversary of the Social Security Act as well as the 50th Anniversaries of Medicare and Medicaid—institutions that have reduced poverty, helped families sustain their standard of living and strengthened the national community. Addressing the retirement income crisis and significant income problems of today’s retirees in a way that recognizes the importance of intergenerational commitments and supports the expansion of the nation’s most successful and popular domestic policy will resonate most effectively with the American people. E. Kingson, Professor of Social Work at Syracuse University is Founding Co-director, Social Security Works and Co-chair of the Strengthen Social Security Coalition. M. Checksfield is Legislative Director of Social Security Works and the Strengthen Social Security Coalition. Partial support for the writing of this article was provided from a grant received by Social Security Works from The Atlantic Philanthropies.
This issue marks a transition point in the life of this journal. Readers who peruse the inside cover of the journal (or our website) will notice that the editorial board has been (thoroughly) renovated. Self-questioning, self-criticism and even a penchant for self-subversion have been constitutive of the identity of the European Law Journal since its foundation. The new editorial board will contribute to keep this identity alive. I am extremely happy to report that the new board is close to complete gender balance (and hopefully will be rather soon in full gender balance). The new board is also more inclusive of the different legal, political and cultural traditions that make up the European legal mosaic. This will certainly lead to new ideas, new debates and new sections, in all cases reflecting an invariable commitment to thinking law in its economic, political, historical, social and cultural context. Never before was the reporting of the content of European law an act so pregnant of radical implications. Never before so much was at stake in Europe: socially, economically and politically. Not since the end of the Second World War was the very identity of European societies as open and cooperative, democratic and socially just societies so much challenged. If the proof of the cake is in the eating, the proof of the journal is in its contents. Both Gareth Davies and Marija Bartl break new ground on subsidiarity. Both authors focus on the structural constitution of power allocation in Europe. Separately, each piece challenges not only the existing literature, but also the practice (and discourse) of European institutions. Jointly, Davies and Bartl redefine the very terms in which the debate on subsidiarity should proceed from now onwards. Tanja Ehnert draws major theoretical and constitutional lessons from the study of what is at first sight the rather specialised if not esoteric subject of nanotechnologies in food (including nanofood). She acknowledges that European institutions produce lots of expertise, but she puts forward powerful reasons to doubt that this expertise amounts to the kind of knowledge which could justify the claim to legitimacy implicit in European practice. The point she raises goes far beyond the specific subject she studies. Nanofood may be physically tiny, but after you read the paper, you will be forced to agree that its legal implications are far from small. Fabien Terpan offers a systematic and theoretically grounded reconstruction of soft law. After the inflation (and recent devaluation) of the concept, it is high time we come to terms with what exactly soft law is and with what we mean when we characterise law as soft. Terpan puts us on a promising track. Marek Szydlo revisits one of the key affirmative action policies in European law: gender equality on company boards. He makes us rethink the legal framework and suggests some reasons why we should be careful when drawing conclusions on the matter. Finally, William Phelan invites us to revisit the very first European ‘troika’, namely the trio of founding cases of European constitutional law. Phelan's work is both a piece of legal history and a very contemporary plea for a different understanding of European law.
Much of the discussion of the ethical concerns involved in the care of those with Disorders of Consciousness (DOC) has been presented in terms of the dichotomous “right to die” / “right to life” (RTD/RTL) framework with nearly singular focus on (1) assessing whether the individual retains “consciousness,” and (2) making the “right” choices about the use of life sustaining treatments (LSTs). However, the lived experience of the family, friends and medical providers who have close contact with individuals with a DOC indicates that the ethical concerns involved cannot be reduced to the RTD/RTL framework, to proofs of consciousness, or to the right to make choices about treatment. Rather than advocate for a “right” choice in regards to use of LST in those with DOC, this essay utilizes the writings of Paul Ricoeur to illuminate the sources of our ethical confusion and to engage in deeper ethical reflection. I describe DOC from the perspective of neuroscience and review recent research. I then critique conceptions of autonomy and personhood within medical ethics, especially in so far as a model of consumer choice dominates conceptions of autonomy and cognitive capacity is considered a determinant of moral worth. I present Ricoeur’s understanding of autonomy as a relational project and his description of individuals as capable and fragile in varying degrees as an alternative. I proceed by examining the concepts of “sanctity of life” and “pain and suffering,” where I use Ricoeur’s description of all humans as acting and suffering, and his description of solicitude as the model for responding to suffering. I conclude with Ricoeur’s description of the ethical intention of “aiming at the ‘good life,’ with and for others, in just institutions” as an approach to analyzing ethical dilemmas and clarifying what it is at stake in various alternatives.
Open access
Mental Health and Psychiatry
Neuroethics, Human Enhancement, Biomedical Innovations
In 1990s the government adopted D-by-D policy with a very good intention of reforming its local governments and let them enjoy the decision making powers promised by the D-by-D policy. One of the crucial of elements of decentralization was fiscal decentralization which gives the local jurisdictions to exercise adequate authority over important decisions with regard to setting development priorities, financing local services, revenue mobilization and expenditure authority continue. This article explored the perception of council on exercise of their fiscal authority in selected local authorities in Tanzania. The findings show that council exercise reasonable authority over revenues mobilization, the setting of the local tax rates and full expenditure authority over the locally generated revenue and also the discretionary grants.
Recent years have seen the emergence of a new class of currencies, called\ncryptocurrencies. These currencies use cryptography to provide security\nand peer-to-peer networking to provide a decentralized system. Bitcoin is\nthe most popular of these currencies. It uses a two-pass\nSHA-256 hash at its core. Producing new bitcoins is done through a process\nreferred to as "mining", which involves a brute-force search for a hash with\na specific value. This process requires large amounts of computing power.\n\nCurrent-generation hardware for bitcoin mining includes highly-optimized\nASIC chips which provide huge amounts of performance. However, designers of\nsuch chips are having problems with delivering enough power and cooling\nto the chips. To alleviate this problem, this thesis looks at the possibilities\nof using heterogeneous computing to reduce power consumption and produce a more\nenergy-efficient mining solution.\n\nA SHA-256 accelerator and a DMA module is developed and integrated into a tile for\nthe Single-ISA Heterogeneous MAny-core Computer, SHMAC, and a system with\nmultiple cores is used to exploit the thread-level parallelism provided by\nthe platform. The system is tested using a benchmark to find out what performance\nand energy efficiency can be expected when using the system for bitcoin mining.\n\nThe results show a maximum performance of 175,7 kH/s when running the benchmark\napplication on 14 cores using the SHA-256 accelerator and the DMA module. The best\nenergy efficiency was obtained when running on 14 cores without the DMA enabled,\nat 163,2 kH/J. The results does not compare well to specialized FPGA-based\nbitcoin miners, but demonstrates the SHMAC platform's large degree of thread-level parallelism\nwhich can be better exploited in other applications.
The Bitcoin cryptocurrency relies heavily on a variety of cryptographic functions and operations, which are currently assumed to be secure, but will inevitably be broken in the future. As Bitcoin tries to compete against traditional currencies, it remains to be seen how the Bitcoin protocol will need to change in response to weakened cryptography. To this end, this study systematically evaluates the effects of broken cryptographic primitives on the operation of the Bitcoin network, and the changes to the Bitcoin protocol that will be necessary in response. We conclude that a broken hash function only requires switching over to a new hash function, without the need to re-write the blockchain, and is well serviced by the “checkpoint” mechanisms already built into Bitcoin. However, a vulnerability of the signature scheme cannot be dealt with in the same manner without side-e.ects, as it may lead to lost or stolen coins, even if the process is gradual and is conducted before the cryptographic primitive is broken. We conclude that solving this problem either requires some degree of centralization, or the use of Zero-Knowledge Proofs along or on top of Bitcoin.
The role of Bitcoin -open source virtual peer-to-peer money -in finance has become more important with the increasing acceptance by service providers. Nevertheless several financial institutes and governments explain their revulsion against Bitcoin, due to the unknown financial risks behind it which could have an impact on the global financial world. In this paper we examine the relationship between BTC/USD exchange rate and the network properties of the underlying transactional graph. The main goal of our research is to get a deeper understanding on the behavior of Bitcoin and ground further researches on exploring the financial risk. To characterize the transactional graph network analysis techniques, while to examine the relationship data mining and time series analysis techniques were used.
Bitcoin is a virtual currency transaction protocol.It also is a type of virtual currency.One of Bitcoin's unique features is that it is decentralized; it is not created or issued by a single person or entity.Rather, it is "mined" by miners that are issued bitcoins in exchange for solving complex math problems with special software.Bitcoins may be converted to governmentissued legal tender (commonly referred to as fiat currency) or other types of virtual currency through an exchange, or they may be used to purchase goods and services from any of the tens of thousands of merchants who accept bitcoins for payment.The Bitcoin protocol enables the transfer of bitcoins and also can be used for other purposes, such as providing the infrastructure for smart contracts, escrow systems, smart property/title systems, and much more.Many other virtual currencies exist.Some are centralized virtual currencies that are created and issued by a single entity.Some of these virtual currencies may be converted to fiat currency, but others may not.Many are "closed loop" virtual currencies that may only be used to obtain goods and services of the issuer.
In this thesis there will be an attempt to model the market price of cryptocurrencies. Since 2010 cryptocurrencies have gone from being fairly unknown to being familiar amongst the general public which increases the need for knowledge on what affects the market price of cryptocurrencies. These connections will be found by statistical analysis and be applied on cryptocurrency data from January 2012 to January 2015. The data will be modeled by linear regression and implemented in R after the data have been formating in Excel. The results suggest that the price of cryptocurrencies depends heavily on the search traffic on the specific cryptocurrency name on Google’s search engine.
Michele Ciampi, Giuseppe Persiano, Luisa Siniscalchi, Ivan Visconti
The Fiat-Shamir (FS) transform is a popular technique for obtaining practical zero-knowledge argument systems. The FS transform uses a hash function to generate, without any further over-head, non-interactive zero-knowledge (NIZK) argument systems from public-coin honest-verifier zero-knowledge (public-coin HVZK) proof systems. In the proof of zero knowledge, the hash function is modeled as a programmable random oracle (PRO). In TCC 2015, Lindell embarked on the challenging task of obtaining a similar transform with improved heuristic security. Lindell showed that, for several interesting and practical languages, there exists an efficient transform in the non-programmable random oracle (NPRO) model that also uses a common reference string (CRS). A major contribution of Lindell’s transform is that zero knowledge is proved without random oracles and this is an important step towards achieving efficient NIZK arguments in the CRS model without random oracles. In this work, we analyze the efficiency and generality of Lindell’s transform and notice a significant gap when compared with the FS transform. We then propose a new transform that aims at filling this gap. Indeed our transform is almost as efficient as the FS transform and can be applied to a broad class of public-coin HVZK proof systems. Our transform requires a CRS and an NPRO in the proof of soundness, similarly to Lindell’s transform. 1
Please find the English version of this paper at http://ssrn.com/abstract=2729548 . Italian Abstract: Nel 2008 il protocollo Bitcoin ha introdotto una nuovo modo di trasferire diritti: il modello di Blockchain, uno schema matematico che combina una serie di algoritmi per procedere all'incorporazione di determinati diritti in una stringa digitale trasferibile. Una delle evoluzioni di quel protocollo è rappresentata dagli smart contract, un modello ancora da definire a nei dettagli tecnici e giuridici in cui alcune clausole del contratto vengono tradotte in codice informatico per l'esecuzione automatica in una blockchain derivata dal protocollo Bitcoin. Questo paper propone una prima valutazione dell'argomento basata sulla ricognizione dello stato dell'arte. English Abstract: In 2008 the Bitcoin protocol has introduced a new way to transfer rights: the blockchain model, a method combining mathematical algorithms in order to secure rights in transferrable digital string. One of the implementations of that system is represented by smart contracts, a model that is still to be defined in technical and legal details. The scheme turns specific contractual provisions in executable digital codes, designed for self execution in a Bitcoin derived blockchain system. This paper proposes a preliminary evaluation based on the state of the art.
In this paper, we concern ourselves with cryptocurrency and how cryptocurrency affects the cryptocurrency market as well as the fiat currency market. The whole topic will be sepreted into two sections: competition among different currencies, as well as competition among exchanges[2]. We aim at figuring out the current circumstance of cryptocurrency which as a casual visitor in the market, and additionaly we will also look at the prospect of cryptocurrency and the currency market. Cryptocurrency with many new features has an uneasy development after entering into the financial market, although it is not yet powerful to compete with fiat currency, the effects of cryptocurrency and cryptocurrency exchange in financial market will still be full of meaning.
Derivatives are financial instruments whose value depend on the values of other, more basic underlying variables. One of the most common and simple derivatives is a futures contract. This manuscript introduces the new kind of futures contracts called non-linear inverse futures contracts (inverse futures in short) firstly introduced by ICBIT trading platform specifically for Bitcoin trading and later picked up by major bitcoin trading platforms.
The role-based access control (RBAC) is a natural and versatile model of the access control principle. In the real world, it is common that an organization provides a service to a user who owns a certain role that was issued by a different organization. However, such a trans-organizational RBAC is not common in a computer network because it is difficult to establish both the security that prohibits malicious impersonation of roles and the flexibility that allows small organizations/individual users to fully control their own roles. This study proposes a system that makes use of Bitcoin technology to realize a trans-organizational RBAC mechanism. Bitcoin, the first decentralized digital currency, is a payment network that has become a platform for innovative ideas. Bitcoin’s technology, including its protocol, cryptography, and open-source nature, has built a good reputation and has been applied in other applications, such as trusted timestamping. The proposed system uses Bitcoin technology as a versatile infrastructure to represent the trust and endorsement relationship that are essential in RBAC and to realize a challenge-response authentication protocol that verifies a user's ownership of roles.
Bitcoin is a decentralized peer-to-peer payment system that has the potential to disrupt the financial industry. In order for the Bitcoin network to function properly, people within the network need to follow the protocol and contribute computing power. However, selfish strategies can be used to disproportionately increase one’s payoff relative to their computational power. Three approaches are used to analyze selfish mining strategies in the Bitcoin network in order to determine when this strategy will dominate.
There are three chapters in my dissertation. In chapter one I study the impact of government corruption on tax avoidance by corporations with tax liability in China. I begin by developing a model of a firm's choice of tax avoidance based on the level of corruption in the firm's province. I show that a higher level of government corruption and a higher tax rate are predicted to increase a firm's tax avoidance. My empirical estimates show that a one-standard-deviation increase in government corruption corresponds to a 6% increase in tax avoidance by firms, based on data from nearly 600,000 firms from 1998 to 2007. When I separate the sample by type of ownership of firms, I find that domestic private firms tend to avoid a larger portion of their tax liabilities than foreign or state-owned firms. I also find that tax avoidance increases when the effective tax rate increases. The size of the firm, age of the firm, and whether the firm exports from China also influence tax avoidance. In chapter two, a joint work with Sergey Mityakov, we study the impact of competition on tax avoidance by corporations in Mexico. Using more than 2,000 firm level data, we show that firms tend to avoid more taxes in less competitive markets, that is more concentrated market. A one standard deviation increase in competition leads to a 7.7% increase in tax avoidance. By splitting the sample based on ownership structure, we show that domestic firms avoid more taxes. When we separate the firms according to the plant size, we find that larger firms tend to avoid more taxes. We find robust and consistent results by using different competition measures and other robustness tests. In chapter three, I theoretically demonstrate how fiscal decentralization affects corruption. The theory predicts that fiscal decentralization reduces corruption. This result is then tested using a panel data set of 31 provincial level government from 1998 to 2007 in China. My estimates suggest that fiscal decentralization in government expenditures and government revenue is negatively correlated with corruption. Using leader and location dummy variables, I find that central government leaders can influence the corruption level in China. I also find that more developed regions in China tend to be less corrupt.