17.5 billion dollars. Between the Transportation Security Administration (TSA) budget, government agency expenditures, and the estimated opportunity costs of the travelling public’s delays and damages, this is how much we as a country put into aviation security in fiscal year 2016. Where does this money go? Why does it cost so much? Are we safe enough? Most importantly, is this cost worth it? In JohnMueller andMarkG. Stewart’s newbook,Are We Safe Enough? Measuring and Assessing Aviation Security, the authors explore the nature of aviation security in the USA. They cite official government reports, stories from the media, and comparisons to other country’s version of our Department of Homeland Security (DHS) and Transportation Security Administration (TSA). Using their consolidated data, they argue that “these considerations are particularly important because it certainly appears that avoiding overreaction is by far the most cost-effective counterterrorism measure.”1 The book attempts to determine the costs and benefits of transportation security spending, including those associated with potential changes to current screening methods. After defining the goals of the TSA and what constitutes a terrorist attack, the authors detail the 21 current layers of aviation security, breaking them down individually, and displaying how effective each layer is at deterring or disrupting a potential terrorist attack. They find that of the twomain terrorist threats, hijacking has approximately a 99.3% chance of being deterred or disrupted, and a passenger-borne bomb attack has a 98% chance of being deterred or disrupted. They conclude that “these levels of risk reduction are very robust” given the standard for acceptable risk.2 They further break down the cost of each layer. The authors use historical terrorist attack data from 1970 to the present as benchmarks for costs, both in lives and economic loss. This enables an analysis of costs that pertain specifically to aviation security. The authors compare the cost of each individual layer. They find that several layers, such as the hardened cockpit door and the Federal Flight Deck Officer program (FFDOs) are effective at preventing hijacking attacks at an exceptionally affordable cost. They also findmarginal cost-effectivemeasures – in regard to thwarting both hijackings and bombings – in the Visual Intermodal Protection Response (VIPR) teams, canine teams, and others. Some of the most expensive and cost-ineffective layers are found to be the Behavioral Detection Officers (BDOs) and the Federal Air Marshal Service (FAMS), as neither layer has been found to adequately protect hijackings or bombing threats. Transportation Security Officers (TSOs) and their duties at checkpoints and as travel document checkers (considered two separate layers) were not found to be cost-effective, either. However, the authors praised the creation of TSA PreCheck, arguing it allows for more efficient screening of nearly half of the traveling public, and more intensive screening of higher risk passengers, thus making overall aviation security safer.3 The authors use their findings on the BDO program and FAMS to argue for the reform or elimination of them, at a savings of hundreds of millions of dollars. They use data from other countries to argue for implementation and expansion of cheaper and more effective options to counter a perceived loss in overall security, including the expansion of the highly effective FFDO program and the installed physical secondary barriers (IPSBs) as a supplement to the deficiencies of the hardened cockpit door.4 The focus shifts from protecting airliners to protecting the airports they fly out of, as intelligence shows them to be an increasingly appealing target for terrorists. Using the same cost-benefit analysis techniques used

中文翻译：

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马克·G·斯图尔特和约翰·穆勒。我们足够安全吗？评估和评估航空安全

175亿美元。在运输安全管理局（TSA）的预算，政府机构的支出以及旅行公众的延误和损害的估计机会成本之间，这是我们一个国家在2016财年投入航空安全的资金。这笔钱去了哪里？为什么要花这么多钱？我们足够安全吗？最重要的是，这笔费用值得吗？在JohnMueller和MarkG中。斯图尔特的新书《我们足够安全吗？测量和评估航空安全，作者探索了美国航空安全的性质。他们引用了政府的官方报道，媒体的报道以及与美国国土安全部（DHS）和运输安全管理局（TSA）的其他国家版本的比较。使用他们的合并数据，他们认为：“这些考虑因素尤其重要，因为显然避免过度反应是迄今为止最具成本效益的反恐措施。” 1该书试图确定运输安全支出的成本和收益，包括与可能发生的变化相关的成本和收益。当前的筛选方法。在确定了TSA的目标以及恐怖袭击的构成之后，作者详细介绍了当前的21个航空安全层，分别对其进行细分，并显示了每一层在阻止或破坏潜在的恐怖袭击方面的有效性。他们发现，在这两种主要的恐怖威胁中，劫持有大约99.3％的机会被阻止或破坏，而载客炸弹袭击有98％的被阻止或破坏的机会。他们得出结论，给定可接受风险的标准，“这些降低风险的水平非常强大”。2他们进一步细分了每一层的成本。作者使用1970年至今的历史恐怖袭击数据作为生命和经济损失成本的基准。这样就可以分析与航空保安有关的成本。作者比较了每个单独层的成本。他们发现，坚固的驾驶舱门和联邦飞行甲板官计划（FFDOs）等几层有效地防止了劫持攻击，而费用却非常低廉。他们还从视觉多式联运保护响应（VIPR）小组，犬队和其他小组中，找到了有效的边际成本效益措施，以制止劫机和轰炸。发现一些最昂贵且成本效益最低的层是行为检测官（BDO）和联邦航空元帅部队（FAMS），因为尚未发现这两个层都不能充分保护劫机或炸弹威胁。运输安全官员（TSO）及其在检查站和旅行证件检查员的职责（被认为是两个独立的层次）也不具有成本效益。然而，作者称赞TSA PreCheck的创建，认为它可以更有效地筛查将近一半的旅行公众，并且可以对高风险旅客进行更深入的筛查，从而使整体航空安全更加安全。3作者将他们的发现用于BDO计划和FAMS主张改革或取消它们，节省了数亿美元。他们利用来自其他国家的数据来主张实施和扩展更便宜，更有效的选择方案，以应对人们认为的总体安全损失，包括扩展高效的FFDO计划和已安装的物理二级屏障（IPSB），作为对安全性的补充。情报显示，它们已成为恐怖分子越来越有吸引力的目标，重点从保护客机转向保护他们飞出的机场。使用与过去相同的成本效益分析技术 包括扩展高效的FFDO计划和安装物理辅助屏障（IPSB），以补充硬化驾驶舱门的缺陷。4据情报显示，重点从保护客机转变为保护他们飞出的机场成为恐怖分子越来越有吸引力的目标。使用与过去相同的成本效益分析技术 包括扩展高效的FFDO计划和安装物理辅助屏障（IPSB），以补充硬化驾驶舱门的缺陷。4据情报显示，重点从保护客机转变为保护他们飞出的机场成为恐怖分子越来越有吸引力的目标。使用与过去相同的成本效益分析技术