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1 IDIC – SANS GIAC LevelTwo ©2000, 2001 1 Network Based Intrusion Detection Tutorial 1 Introduction to the basic approaches and issues of Intrusion Detection Hello! Welcome to the first half of our network based intrusion detection tutorial, where we will introduce you to the basic approaches of intrusion detection. In this section, we will discuss a rule- based analysis process by going through the topics listed on your next slide. At the end of the section we will talk about some of the methods currently used to perform intrusion detection. 2 IDIC - SANS GIAC LevelTwo ©2000, 2001 2 • False positives, False negatives • EOI, dictionary signatures, profile changes • Severity = (criticality + lethality) – countermeasures (system + network) • Long term conditions Before We Begin We will begin our discussion by talking about false positives and false negatives, which are ever present factors in the life of an intrusion analyst. We will then discuss the notion of Events of Interest (EOI), and their relevance to the event analysis process. We will also go over techniques for judging the severity of a particular event. Additionally, we will propose a way to handle long term conditions that might result from a prolonged exposure to attacks. 3 IDIC - SANS GIAC LevelTwo ©2000, 2001 3 Sources of Data All data: observable or not Collectable Events of Interest There are very few situations in which we are able to collect all the data. We need to develop techniques that allow us to routinely locate Events of Interest (EOI) in the data we are able to collect, so that we know where to focus our attention. 4 IDIC - SANS GIAC LevelTwo ©2000, 2001 4 False Positives and Negatives False positives False negatives All Data Real EOI False positives are “false alarms.” The detects match only some of the criteria for indicators of possible intrusion. False positives tend to wear down incident handling resources and make us slower to react in the future. False negatives are the actual intrusions and intrusion attempts that we do not detect. These can allow an adversary to establish a significant presence in our information systems before we begin to react. 5 IDIC - SANS GIAC LevelTwo ©2000, 2001 5 What Are Events Of Interest • Since we can’t collect, store, or analyze all possible events, we focus our collection efforts on stuff that might prove useful, EOI. – Dictionary: known attack signatures, known attackers – Short term significant changes in system or user profile The reality of limited computing and personnel resources is such that we cannot collect, store, and analyze all possible events. Therefore, analysts tend to focus their collection efforts on events that might prove useful – Events of Interest (EOI). Unfortunately, focusing helps reduce the false alarms or false positives, but increases the chance of missing an EOI. One of the ways to help ensure that an EOI is not missed is to compare suspicious events against a dictionary of known attacks or attackers. You can’t afford not to test against a dictionary! Another way to widen our field of vision is to monitor for changes in system or user profiles. Consider the following example: You have noticed an increase in the number of probes and intrusion attempts at your site. DNS and mail relay systems are always high profile targets, so you are Confronting Objections to the Economic Approach Confronting Objections to the Economic Approach By: OpenStaxCollege It is one thing to understand the economic approach to decision-making and another thing to feel comfortable applying it The sources of discomfort typically fall into two categories: that people not act in the way that fits the economic way of thinking, and that even if people did act that way, they should try not to Let’s consider these arguments in turn First Objection: People, Firms, and Society Do Not Act Like This The economic approach to decision-making seems to require more information than most individuals possess and more careful decision-making than most individuals actually display After all, you or any of your friends draw a budget constraint and mutter to yourself about maximizing utility before you head to the shopping mall? Do members of the U.S Congress contemplate production possibilities frontiers before they vote on the annual budget? The messy ways in which people and societies operate somehow doesn’t look much like neat budget constraints or smoothly curving production possibilities frontiers However, the economics approach can be a useful way to analyze and understand the tradeoffs of economic decisions even so To appreciate this point, imagine for a moment that you are playing basketball, dribbling to the right, and throwing a bounce-pass to the left to a teammate who is running toward the basket A physicist or engineer could work out the correct speed and trajectory for the pass, given the different movements involved and the weight and bounciness of the ball But when you are playing basketball, you not perform any of these calculations You just pass the ball, and if you are a good player, you will so with high accuracy Someone might argue: “The scientist’s formula of the bounce-pass requires a far greater knowledge of physics and far more specific information about speeds of movement and weights than the basketball player actually has, so it must be an unrealistic description of how basketball passes are actually made.” This reaction would be wrongheaded The fact that a good player can throw the ball accurately because of practice and skill, 1/7 Confronting Objections to the Economic Approach without making a physics calculation, does not mean that the physics calculation is wrong Similarly, from an economic point of view, someone who goes shopping for groceries every week has a great deal of practice with how to purchase the combination of goods that will provide that person with utility, even if the shopper does not phrase decisions in terms of a budget constraint Government institutions may work imperfectly and slowly, but in general, a democratic form of government feels pressure from voters and social institutions to make the choices that are most widely preferred by people in that society So, when thinking about the economic actions of groups of people, firms, and society, it is reasonable, as a first approximation, to analyze them with the tools of economic analysis For more on this, read about behavioral economics in the chapter on Consumer Choices Second Objection: People, Firms, and Society Should Not Act This Way The economics approach portrays people as self-interested For some critics of this approach, even if self-interest is an accurate description of how people behave, these behaviors are not moral Instead, the critics argue that people should be taught to care more deeply about others Economists offer several answers to these concerns First, economics is not a form of moral instruction Rather, it seeks to describe economic behavior as it actually exists Philosophers draw a distinction between positive statements, which describe the world as it is, and normative statements, which describe how the world should be For example, an economist could analyze a proposed subway system in a certain city If the expected benefits exceed the costs, he concludes that the project is worth doing—an example of positive analysis Another economist argues for extended unemployment compensation during the Great Depression because a rich country like the United States should take care of its less fortunate citizens—an example of normative analysis Even if the line between positive and normative statements is not always crystal clear, economic analysis does try to remain rooted in the study of the actual people who inhabit the actual economy Fortunately however, the assumption that individuals are purely self-interested is a simplification about human nature In fact, we need to look no further than to Adam Smith, the very father of modern economics to find evidence of this The opening sentence of his book, The Theory of Moral Sentiments, puts it very clearly: “How selfish soever man may be supposed, there are evidently some principles in his nature, which interest him in the fortune of others, and render their happiness necessary to him, though he derives nothing from it ...[...]... began to read mathematics on my own One thing led to the next, and by the mid-1970s, I completed my PhD thesis at Princeton applying game theory to foundational issues in political and moral theory My great good fortune was to have chosen as my thesis topic the problem of distributive justice, that is, the issue of who owes how much to whom, and why This topic had been moribund for decades until the. .. developments over the past half-century have contributed to today’s Dialogue of the Deaf These range from the culture wars of the 1960s and 1970s, to the triumph of inductive logic, to significant changes in lifestyle, and to the advent of extensive Congressional gerrymandering It will be helpful to review the role played by each The Culture Wars To a certain extent, the “culture wars” of the late 1960s and 1970s... institute, he explained to me that the identity bestowed by such labeling was “very good for the funding of contract research.” To be sure, there are a number of commentators who do not fall into these categories Nonetheless, the tenor of the times is the crossfire between Fox News and MSNBC The result is that we are all losers The Price Paid: Policy Gridlock Perhaps the most serious price we are paying for... morphed into a shouting match in which there is no recognition that win-win solutions exist But they do exist, and they are exactly what the doctor ordered Such policies are needed to build bipartisan support on issues, and thus to terminate gridlock here in America, and gridlock elsewhere for that matter My third goal is to demonstrate that the win-win solutions I deduce for the five problems analyzed are. .. example, the prospect of a Lost Decade, and ballooning U.S health-care spending I believe these to be novel solutions, and in arriving at them, I have drawn upon new and quite sophisticated theories that are based upon deductive logic These are the levers and pulleys that make it possible to identify new policy solutions This book has three goals The first is to identify five important problems confronting the. .. categories that have ceased to be meaningful does not seem to bother anyone The possibility that a compelling middle ground might exist seems to have evanesced into thin air And once you are tagged as on the Left, then you must remain on the Left, and vice versa Even entire think tanks are now regularly tagged Left of center” or Right of center.” When I made this point to the head of a very prestigious... ubiquitous throughout the Western world today Whether today’s anxiety stems from the inability of politicians in Washington, DC, to fund the U.S welfare state, or from the intractable euro crisis in Europe, there is a rising sense of gloom and helplessness on both sides of the Atlantic I am an optimist, and this book is offered as an antidote to this Foreign Trade University Faculty of Economics and International Bussiness Development Economics Group assignment EFFECTS OF CLIMATE CHANGE ON THE ECONOMIC DEVELOPMENT OF VIET NAM Instructor: MA. Nguyen Thi Hai Yen Group 10 Students: Nguyen Thanh Nam Vu Khanh An Nguyen Quang Huy Le Huu Trung Le Hai Hung Nguyen Ngoc Dung Foreign Trade University Development Economics Group 10 Le Thi Dieu Linh Nguyen Thanh Tung Ha Noi, May 2014 Group 10 Page 2 Foreign Trade University Development Economics Group 10 Outline Literature Review There are many studies that have examined the effects of climate change on Vietnam’s economy. The majority of findings stated that climate change have negative impacts on Vietnam’s economy and suggest possible adaptation or mitigation measures to lessen the adverse impacts. The economies of some countries are more vulnerable to climate change than the global average, according to a report by World Bank (2009), Vietnam is one of the five countries predicted to be among the most affected by climate change due to its long coastlines. According to Tran Duc Vien in Climate change and its impact on agriculture in Vietnam, it is believed that climate change is going to have huge impact on people’s health since the rising of temperatures is a good conditions for diseases such as malaria to develop. Claudia Ringler (climate change impacts in Vietnam: potential for agricultural mitigation) stated that adverse impacts of climate change can affect economic growth, poverty and malnutrition. The third world is more likely to have a larger scale of their economies in agriculture and forestry. Climate change surely decrease the productivity of the agriculture due to its increasing heat of global warming Low-latitude countries suffer up to four-fifth of the negative impacts of climate change (Mendelsohn et al. 2006), While the negative impacts of climate change is clear, some still is optimistic about the outlook of the future world’s economy, Robert Mendelsohn (climate change and economic growth) argues that the impacts from climate change are not likely to affect the growth of global economy for the next four decades. These impacts are simply not large enough to affect economic growth this century. Group 10 Page 3 Foreign Trade University Development Economics Group 10 However some also said that although it’s a challenge, climate change also has some forgotten benefits. Matt Ridley (Why Climate Change Is Good for the World) has said: “Climate change has done more good than harm so far and is likely to continue doing so for most of this century. This is not some barmy, right-wing fantasy; it is the consensus of expert opinion. Yet almost nobody seems to know this.” According to what he stated in his research, climate change had bring many benefits to human, such as improvement in global economic, fewer winter death, lower energy cost, better agricultural yields and many others advantages. The adaptation and mitigation measures are also mentioned in many studies. For example, in the IPCC Fourth Assessment Report: Climate Change 2007, the August 18, 2007 Time: 11:06am chapter13.tex Utilitarian Pricing of Annuities • 111 Figure 13.1. First-best allocation of utilities. while V ∗ h = (1 + p h ) u R H h=1 (1 + p h ) . Thus, the utilitarian first best has inequality in expected utilities but may have equality in consumption levels (Arrow, 1992). This result is similar to Mirrlees’ (1971) optimum income tax model where individuals differ in productivity. 2 The first best allocation pro- vides higher (expected) utility to those with a higher capacity to produce utility. In the appendix to this chapter it is shown that 0 > 1 + p n c ∗ h ∂c ∗ h ∂p h > −1, (13.7) while ∂c ∗ h /∂p j 0, for j = h, h, j = 1, 2, , n. 2 In Mirrlees’ model with additive utilities, the first best has all individuals with equal consumption, and those with higher productivity, having a lower disutility for generating a given income, are assigned to work more and hence have a lower utility. August 18, 2007 Time: 11:06am chapter13.tex 112 • Chapter 13 Concavity of u and (13.7) imply ∂V ∗ h ∂p h = u(c ∗ h ) + (1 + p n )u (c n ) ∂c ∗ h ∂p n > 0, (13.8) while ∂ V ∗ h /∂p j 0, j = h, j = 1, 2, ,H. 3 Thus, with the given total resources, an increase in one individual’s survival probability decreases his or her optimum consumption, but the positive effect of higher survival probability on expected utility dominates. The effect on the welfare of other individuals facing only resource redistribution depends on the shape of the social welfare function. 13.2 Competitive Annuity Market with Full Information In a competitive market with full information on the survival proba- bilities of individuals and a zero rate of interest, the price of a unit of second-period consumption, c 2h , is equal to the survival probability of each annuitant. Individuals maximize expected utility subject to a budget constraint c 1h + p h c 2h = y h h = 1, 2, , H, (13.9) where y h is the given income of individual h. Demands for first- and second-period consumption (annuities), c 1h and c 2h , are given by c 1h = c 2h = c h = y h /(1 + p h ). The first-best allocation can be supported by a competitive annuity market accompanied by an optimum income allocation. Equating con- sumption levels under competition, c h , to the optimum levels, c ∗ h (p), yields unique income levels, y h = (1+ p h )c ∗ h (p), that support the first-best allocation. In particular, with an additive W, all individuals consume the same amount: c ∗ h = R H h=1 (1 + p h ) , hence y h = 1 + p h H h=1 (1 + p h ) R. (13.10) 3 In the extreme case when W = min[V 1 , V 2 , ,V H ], optimum expected utilities, V ∗ h = (1 + p h )u(c ∗ h ), are equal, and hence optimum consumption, c ∗ h , strictly decreases with p h (and increases with p j , j = h). August 18, 2007 Time: 11:06am chapter13.tex Utilitarian Pricing of Annuities • 113 13.3 Second-best Optimum Pricing of Annuities Governments do not engage, for well-known reasons, in unconstrained lump-sum redistributions of incomes. In contrast, most annuities are supplied directly by government-run social security systems and taxes/subsidies can, if so desired, be applied to the prices of annuities offered by private pension funds. These prices can be used by govern- ments to improve social welfare. Although deviations from actuarially fair prices entail distortions (i.e., efficiency losses), distributional im- provements may outweigh the costs. 4 Suppose that individual h purchases annuities at a price of q h .With an income y h , his or her budget constraint is c 1h + q h c 2h = y h , h = 1, 2 ,H. (13.11) Maximization of (13.2) subject to (13.11) yields demands c ih = c ih (q h , p h , y h ), i = 1, 2, and h = 1, 2, ,H. Maximized expected utility, V h ,is V August 18, 2007 Time: 10:40am chapter11.tex CHAPTER 11 Life Insurance and Differentiated Annuities 11.1 Bequests and Annuities Regular annuities (sometimes called life annuities) provide payouts, fixed or variable, for the duration of the owner’s lifetime. No payments are made after the death of the annuitant. There are also period-certain annuities, which provide additional payments after death to a beneficiary in the event that the insured individual dies within a specified period after annuitization. 1 Ten-year- and 20-year-certain periods are common (see Brown et al., 2001). Of course, expected benefits during life plus expected payments after death are adjusted to make the price of period- certain annuities commensurate with the price of regular annuities. These annuities are available in the United Kingdom, where they are called protected annuities. It is interesting to quote a description of the motivation for and the stipulations of these annuities from a textbook for actuaries: These are usually effected to avoid the disappointment that is often felt in the event of the early death of an annuitant. The calculation of yield closely follows the method used for immediate annuities and this is desirable in order to maintain consistency. The formula would include the appropriate allowance for the additional benefit. (Fisher and Young, 1965, p. 420.) The behavioral aspect (disappointment) may indeed be a factor in the success of these annuities in the United States and the United Kingdom. Table 11.1 displays actual quotes of monthly pensions paid against a deposit of $100,000 at different ages. It is taken from Milevsky (2006, p. 111) and represents the best U.S. quotations in 2005. The terms of period-certain annuities provide a bequest option not offered by regular annuities. It has been argued (e.g., Davidoff, Brown, and Diamond, 2005) that a s uperior policy for risk-averse individuals who have a bequest motive is to purchase regular annuities (0-year in table 11.1) and a life insurance policy. The latter provides a certain amount upon death, while the amount provided by period-certain annuities is random, depending on the age at death. 1 TIAA-CREF, for example, calls these After-Tax Retirement Annuities (ATRA) with death benefits. August 18, 2007 Time: 10:40am chapter11.tex 82 • Chapter 11 Table 11.1 Monthly Income from a $100,000 Premium Single-life Pension Annuity (in $). Period=certain Age 50 Age 65 Age 70 MFMFMF 0-year 514 492 655 605 747 677 10-year 509 490 630 592 694 649 20-year 498 484 569 555 591 583 Notes: M, male; F, female. Income starts one month after purchase. In a competitive market for annuities with full information about longevities, annuity prices vary with annuitants’ life expectancies. Such a separating equilibrium in the annuity market, together with a competitive market for life insurance, ensures that any combination of period-certain annuities and life insurance is indeed dominated by some combination of regular annuities and life insurance. The situation is different, however, when individual longevities are private information that is not revealed by individuals’ choices, and hence each type of annuity is sold at a common price available to all potential buyers. In this kind of pooling equilibrium, the price of each type of annuity is equal to the average longevity of the buyers of this type of annuity, weighted by the equilibrium amounts purchased. Consequently, these prices are higher than the average expected lifetime of the buyers, reflecting the adverse selection caused by the larger amounts of annuities purchased by individuals with higher longevities. 2 When regular annuities ... cases, there is no way to increase the quantity of one good without decreasing the quantity of the other Similarly, when an individual makes a 3/7 Confronting Objections to the Economic Approach. .. indeed, neither intends to promote the public interest, nor knows how much he is promoting it By preferring the support of domestic to that of 4/7 Confronting Objections to the Economic Approach. .. in the way described in this chapter? 6/7 Confronting Objections to the Economic Approach Critical Thinking Questions What assumptions about the economy must be true for the invisible hand to