導讀
在1999年，零利率下限（the Zero Lower Bound）在美國還沒有被視作一個迫近的問題。那時的經濟還十分蓬勃，當年底的目標聯邦基金利率為5-1/2個百分點。在那之前，零負利率的僅有參照點來自於20世紀30年代的大蕭條和90年代的日本。對於戰後的歐洲和美國而言，這一經驗則是完全不存在的。
然而，以馬文·古德弗倫德（Marvin Goodfriend）為代表的少數經濟學家則提出這些問題：零利率下限是否會在美國形成挑戰？如果會的話，可能的後果和補救辦法是什麼？研究者和政策制定者們就此展開了關於零利率的探討。
馬文·古德弗倫德強調，美聯儲的資產購置會影響金融形勢，進而影響到經濟體。問題的探討由傳統貨幣政策擴展到了非傳統的手段，例如資產負債表。更重要的是，正如日本央行當時的舉措，央行收購的短期政府債券應當與長期債券區分開來。馬文·古德弗倫德認為零利率下的短期債券是無效的，而長期債券則因投資者的“優先置產”動機而更具潛在影響力。大尺度下的資產購置在之後成為了美國和其他國家緩衝金融形勢的重要工具。
作者 | 約翰·威廉姆斯（John C Williams），美國紐約聯邦儲備銀行總裁
英文原文如下：
Research, policy, and the zero lower bound
Remarks by Mr John C Williams, President and Chief Executive Officer of the Federal Reserve Bank of New York, at the Shadow Open Market Committee Spring Meeting, New York City, 6 March 2020.
Good afternoon. I would like to start by thanking Athanasios for inviting me to participate in this event. It is a real honor to highlight the influence of our esteemed colleague Marvin Goodfriend, an outstanding and original researcher, policy advisor, and friend.
Marvin epitomized the role of policy advisor. His research dug deep into the issues, introduced new ideas into the discussion, and developed options for policymakers to consider for the most challenging issues. The fact that we have so many researchers and policymakers here is testament to the importance of his research in shaping the conversations that we are having to this day.
Before I reflect more on Marvin’s contributions to monetary policy, I should give the standard Fed disclaimer that the views I express today are mine alone and do not necessarily reflect those of the Federal Open Market Committee or others in the Federal Reserve System.
In preparation for what I know will be a stimulating discussion, I’d like to highlight a few of the ways that Marvin changed the conversation in the U.S. about what was then commonly referred to as the zero lower bound on interest rates, or ZLB for short. These show how Marvin’s insights shaped some of the most prominent discussions in monetary policy.
Before I do so, it’s helpful to look back about 20 years. As the clock ticked down on the 20th century, many people’s attention was not on the ZLB. Most were more concerned about the millennium bug that had the world on high alert.
Truth be told, the ZLB wasn’t perceived to be a looming problem in the United States back in 1999. The economy was doing very well and the target federal funds rate was 5-1/2 percent at the end of the year. Up until then, the only historical reference points for the ZLB were from the Great Depression of the 1930s and, more recently, Japan in the 1990s. It was simply not part of the experience of postwar Europe or the Americas.
However, a small group of economists, with Marvin at the forefront, was asking whether the ZLB could pose a challenge here in the U.S. and, if so, what would be the consequences and potential remedies. Researchers and policymakers began to turn the dial up on the discussion around the ZLB.
On those occasions, Marvin emphasized the importance of the ZLB as a constraint on policy and urged us to think differently about how central banks could still carry out their missions, even under that constraint. He developed and analyzed what were then considered “outside the box” options for overcoming the ZLB. These helped lay the groundwork for how economists and policymakers think about these issues in both conceptual and practical terms.
The Fed held a conference in Woodstock, Vermont in October 1999 on the ZLB. At that conference, Marvin presented his paper “Overcoming the Zero Bound on Interest Rate Policy,” which was subsequently published in the Journal of Money, Credit and Banking (JMCB). In January 2002, Marvin briefed the FOMC on aspects of the research that he had presented at the Woodstock conference, as part of a session on the ZLB in which David Reifschneider and I presented our research as well. By that point, the federal funds rate had fallen to 1.75 percent, so the ZLB was starting to get on policymakers’ radar screens.
For example, Marvin was one of the first people to think seriously about how the constraint caused by the ZLB could be relaxed by implementing negative interest rates. Now, I know that the topic of negative interest rates is controversial. But, whatever conclusions you may draw about the relative merits of negative rates, Marvin’s research early on helped identify and explore a broad dimension of issues and potential choices for policymakers.
Marvin’s intellectual pursuit of all aspects of the ZLB logically drove him to explore the possibility for currency to have a digital component. Although many think of central bank digital currencies as a new-fangled idea, Marvin was thinking deeply about the prospect long ago. This has become one of the hot topics in the world of central banks today.
The conversation that Marvin began in Woodstock in 1999 became the basis for discussions that were had later on at the FOMC meeting in January 2002. At that FOMC meeting, Marvin expanded upon the idea of asset purchases as a policy tool that he had proposed in his paper at the conference in Woodstock.
He emphasized that the Fed asset purchases can affect financial conditions and thereby the economy. He was expanding the conversation away from thinking about conventional monetary policy to unconventional options, like the balance sheet. Importantly, he distinguished between central bank purchases of short-term government securities, as the Bank of Japan was doing at that time, versus purchases of longer-term securities. Marvin viewed purchases of short-term securities as ineffective under the ZLB, while he saw purchases of longer-duration securities as potentially powerful owing to a “preferred habitat” motive on the part of investors. Of course, large-scale asset purchases later became a tool of critical importance for easing financial conditions in the United States and abroad.
Although the consequences of the predicted Y2K glitch were minimal, the ZLB became a central issue when the financial crisis hit. Thankfully, Marvin, along with others, helped lay the intellectual groundwork and created the vocabulary for us to work through some of the most significant issues facing central banks. His work is a true emblem of how researchers play a vital role in informing and shaping the policy discussion.
I look forward to the upcoming conversation. Thank you.
編譯 何映儒
編輯 李錦璇
來源 Federal Reserve Board
審校 金天、蔣旭
監製 朱霜霜
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中國人民大學國際貨幣研究所（IMI）成立於2009年12月20日，是專注於貨幣金融理論、政策與戰略研究的非營利性學術研究機構和新型專業智庫。研究所聘請了來自國內外科研院所、政府部門或金融機構的90餘位著名專家學者擔任顧問委員、學術委員和國際委員，80餘位中青年專家擔任研究員。
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