Steve Hanke：夸夸其谈的公共设施
经济政策总受社会风潮影响，最新趋势是公共设施（public infrastructure）。这一趋势的支持者包括政界左派的进步派（progressives），比如巴拉克·奥巴马（Barack Obama），希拉里·克林顿（Hillary Clinton）和伯尼·桑德斯（Bernie Sanders）；还包括右派的民粹主义者（populists），如新当选总统唐纳德·特朗普（Donald Trump）。这些人告诉我们要打碎财政纪律的桎梏，花钱建造公共设施——这剂万能药会医好所有经济弊病。
从全球来看，经济增长依然没有起色，美国是一个重要的例子。自2009年经济衰退以来已有8年多，美国始终未能反弹。经济可能在增长，但扩张速度低于其趋势增长率。美国总需求（国内最终销售额最能体现），名义增长率为2.8％，远低于4.7％的趋势增长率。
一、关于“长期增长停滞”（secular stagnation）的争论
许多人认为，财政紧缩是增长乏力的重要原因，他们主张通过增加公共基础设施建设的这种财政刺激方式来提振经济。另一用以支持增加公共设施支出的论据基于“长期增长停滞”。其主要倡导者是哈佛经济学家和前美国财长拉里·萨默斯（Larry Summers）。他认为民营企业投资不足时，政府必须干预，投资于公共设施建设。
萨默斯指出，国内私有资本支出疲软是他的论点依据。图表显示，国内私营企业净投资相对较弱，数十年来一直处于下降趋势。
因为投资促进生产力，所以投资一旦减少，美国生产力下降就在预料之中了。生产力增长乏力，一直趋于下降。自上世纪70年代末以来，美国就一直处于生产力下降的漩涡中难以脱身。长期增长停滞理论的支持者认为，私人投资净额的不足以及由此产生的生产率下滑可以由公共设施支出来弥补。
二、避免财政紧缩
公共设施建设的想法在过去多次被提及，但似乎逐渐成为防止财政紧缩的手段。如果公共设施建设按预计进行，政府的融资幅度将非常惊人。麦肯锡全球研究院估计，2013 - 30间，全球每年支出3.7万亿美元是“必需”的。
特朗普也紧跟上了这波基建的潮流，提出了一项1万亿美元的公共设施建设计划。但是基建的这些所谓好处经常被夸大，而基建的成本却被低估或扭曲。
关于公共设施支出的经济乘数的分析——部分研究估计为1.6，因为错误的假设而经常出现缺陷，而且基建支出的乘数效应也会因为人为通胀的存在而被夸大。
一旦公共设施建成，人们就会对所谓的利益夸夸其谈。这些项目没有得到很好的维护，用户没有为所使用设施缴纳费用，或者收取的费用远低于相关成本。水是一个典型的例子——输送到供水系统的有平均34％的水被偷走或泄漏。当现有输水系统中的水大量白白流走时，花大把钱来对系统扩容无疑是荒谬的。当把被偷走的或泄露的水考虑在内时，用“乘数”吹起来的基建的所谓好处实际上寥寥无几。
三、基础设施资金的现实
基础设施项目经常面临成本超支的情况。虽然这些项目纸面上看起来不错，但现实完全不同。详细研究表明，美国公共设施项目的实际成本与估计成本的平均比例通常在1.25至2以上。
除了成本超支外，基础设施融资还需征收税款，而征收的税额超出了收入金额。过度的税收负担包括“不必要”（dead-weight）的经济扭曲、执行成本和税运行成本。简言之，要融资一美元，政府的花费要花比一美元多。平均而言，这个花费在1.50美元到1.60美元之间。
考虑到成本超支和收税的成本，人们想知道是否有任何公共设施项目可以证明政府融资的合理性，更不用说融资到1万亿美元。这是个浪费、欺诈和滥用基础设施的奇妙世界。
原文如下：
Economic policy is subject to fads and fashions, and the latest trend is public infrastructure. Its advocates include progressives on the left of the political spectrum, like Barack Obama, Hillary Clinton and Bernie Sanders, and populists on the right, including President-elect Donald Trump. They tell us to remove the chains of fiscal austerity and spend on public works, and that this elixir will cure all economic ills.
Globally, economic growth remains muted, and the US provides an important example. It has been over eight years since the 2009 recession, and the US has failed to bounce back. The economy may be growing, but the pace of expansion is below its trend rate. US aggregate demand, which is best represented by final domestic sales, is growing at a nominal rate of 2.8%, well below the trend rate of 4.7%.
1.The secular stagnation argument
Many argue that fiscal austerity has been responsible for keeping growth down. They advocate fiscal stimulus instead, through spending on public works. Another line of argument used to support increased spending on public works is based on ‘secular stagnation’. Its leading advocate is Larry Summers, Harvard economist and former US Treasury secretary. He argues that private enterprise is failing to invest and that the government must step in and spend on public works.
Summers points to anaemic private domestic capital expenditure as evidence for his thesis. The Chart shows that net private domestic business investment is relatively weak and has been on a downward course for decades.
Investment fuels productivity. So, with little fuel, one should expect weak US productivity numbers. Productivity growth is indeed weak and has been trending downward. The US is in the grips of the longest slide in productivity growth since the late 1970s. Advocates of the secular stagnation theory assert that the deficiency in net private investment and the resulting productivity slump can be made up by public works spending.
2.Escaping fiscal austerity
This argument has been put forward many times in the past, but seems to be gaining ground as a means of escaping fiscal austerity. If proposed public works proceed as projected, the government financing magnitudes would be stunning. The McKinsey Global Institute estimated that annual spending of $3.7tn per year between 2013-30 was ‘required’ worldwide.
Trump has jumped on this infrastructure bandwagon by proposing a $1tn public works programme. But the alleged benefits of infrastructure spending are often wildly inflated, with cost estimates downplayed or distorted.
Analysis of the economic multiplier of infrastructure spending – around 1.6 by some estimates – is often flawed due to incorrect assumptions, and can be subject to misuse in the artificial inflation of benefits.
Once public works are installed, the hot air comes out of their alleged benefits. These projects are poorly maintained, and users are often not charged for what they use, or they are charged prices set well below the relevant costs incurred. Water is a classic case – on average 34% of the water delivered to water systems is either stolen or leaks out of distribution systems. It is hard to take seriously claims that billions of dollars are required to develop more water resource capacity when much of the water produced in existing systems leaks away. Adjusting for leaks and thefts, the alleged benefits for many new projects, which have been inflated by ‘multipliers’, wither away to almost nothing.
3.The reality of infrastructure funding
Infrastructure projects are always subject to cost overruns. While the projects might look good on paper, the reality is very different. Detailed studies show that the average ratios of actual costs to estimated costs for public works projects in the US typically range from 1.25 to over 2.
In addition to cost overruns, the financing of infrastructure requires the imposition of taxes, and taxes impose costs beyond the amount of revenue raised. The excess burdens of taxation include ‘deadweight’ distortions, enforcement and compliance costs. In short, it costs more than a dollar to finance a dollar in government spending. The best estimates indicate that, on average, it costs between $1.50 to $1.60 to raise a dollar in tax revenue.
Taking proper account of cost overruns and the costs of collecting taxes, one wonders if there are any public works projects that could justify federal financing, let alone financing to the tune of $1tn. This is the wonderful world of infrastructure waste, fraud, and abuse.