Zaw Thiha Tun 2015年9月2日
通脹影響我們身邊的所有事物，從例如衣食住行這樣的必需品到生活的各個方面。而且，它能輕易的減少我們的存款。它會使我們現在的存款在未來價值降低。在本文中，我們將會闡述在美國通脹背後的基本面因素，包括成本推動式通脹、 需求拉動式通脹和消費者對通脹的預期。
通脹簡介
但是在深入讨論之前，我們先來了解一下通脹和價格指數在測量通脹中的作用。大多數經濟書籍把通脹定義成經濟體總體價格的持續上升。這就意味著貨幣喪失購買力。在未來相同金額的貨幣只能購買更少的商品和服務。通脹和緊縮是相反的，緊縮時總體價格水平大幅下降，其通脹率為負。通脹率為價格指數的百分比變化。中央銀行密切關註通脹率，因為它是推動貨幣政策的主要因素。發展中經濟體的中央銀行，包括美聯儲，通常希望把通脹率維持在每年2%。
價格指數
正如前面提到的，通脹率由價格指數的變化決定。在美國，被引用和分析最多的是城鎮居民消費價格指數，該數據由勞工統計局每月發佈。城鎮居民消費指數是一個商品和服務的加權，包括食品、飲料、教育和娛樂。其次被引用最多的是生產價格指數，其中包含燃料和農產品，化工產品和金屬。生產指數報告影響國内生產商的價格變化，而且你可以經常看到這些價格變化在一段時間之後在消費價格指數上轉嫁給消費者。
在測量通脹率時一個重要的區別是整體通脹和核心通脹。整體通脹反映在一個國家的所有商品和服務上的通脹。核心通脹是整體通脹減去食品和能源。2015年4月的城鎮居民消費價格指數比三月上漲0.1%，年度增長0.2%。去除食品和能源後，核心通脹同比增長1.8%。這仍然低於美聯儲2%的目標。
成本推動式通脹
成本推動式通脹是兩個主要的通脹類型之一。它是指生產成本上升，導致價格壓力增加。成本推動式通脹一個可能的迹象是大宗商品價格上升，因為像原油和金屬這樣的大宗商品是主要的生產投入。
然而證據表明，非石油大宗商品價格和通脹之間的關系自20世紀80年代就已經被破壞了。分析人士和制定者現在通過失業率觀察勞動力市場，因為勞動力是最重要的生產投入。因為勞動力短缺可以創造提高工資的壓力，勞動力短缺越嚴重失業率就越低。此外，由於勞動力市場的結構性力量，勞動力瓶頸的可能性在失業率達到零之前很久就產生。在失業率下面的工資增長壓力被稱為非加速性失業增長率。
需求拉動式通脹
需求拉動式通脹是一個供應方面的問題，需求拉動式通脹是由高需求引起的價格增長引起的。需求拉動式通脹可以由以下因素引起：
擴張性財政政策。通過降低稅收,政府可以增加對企業和消費者的可支配收入。企業可以把錢花在資本的改進、員工薪酬或新招聘等等。消費者可以購買更多不必要的物品。此外，隨著政府通過增加開支刺激經濟，例如開始大規模基礎設施建設，對商品和服務的需求將會增加，導致價格增長。
貨幣貶值。貨幣貶值可以增加出口和對我們商品和服務的總需求。需求增加導致價格上升。貨幣貶值還能導致進口減少。這可能導致成本推動式通脹。
擴張性貨幣政策
通過公開市場操作，央行可以增加貨幣供給並創建過剩的流通性，這將相對商品降低貨幣的價值。換句話說，通過增加貨幣供給，經濟體内所有參與者購買力增加，導致整體需求的上升。如果商品供應不能適應過剩需求，價格將會上升。就像貨幣學派總結的那樣，過多的錢追逐太少的商品。或者政府可以通過降低利率誘導他們借貸，從而增企業擴張投資和家庭用品的需求。
通脹預期
除了成本推動式通脹和需求拉動式通脹，通脹預期在一個經濟體的影響不能被誇大。一旦通脹在一個經濟體足夠普遍，進一步通脹的預期將會成為最主要的擔憂因素。這些預期將會成為這些經濟體行為背後的指導原則，導致通脹持續增長。我們在20世紀70年代和80年代的歐洲和美國遇到過這種情況，即使在經濟衰退通脹率還是很高。最終導致高失業率和高通脹的滞漲。
盡管通脹預期在政府觀調查外很能觀察，間接測量這些預期的一個方法是通過政府發佈的挂鈎債券和其他政府發行的其他沒有通脹保護的債務工具之間的利差。例如10年期債券收益率為4%，十年期挂鈎債券收益為2%，那麼我們可以推斷在未來十年年通脹率為2%。
總結
美國的通脹壓力可以歸結為以下三個主要因素：生產投入成本增加，整體需求增加和未來通脹的消費者預期。在這三種通脹中，在最近幾年中需求拉動式是最主要的，因為世界各地的政府都在推出寬松貨幣政策以促進經濟增長。美聯儲在十年來首次提供短期利率，全球資本市場的走勢將會跟隨美國的通脹率。直到美聯儲確定立場之前，通脹率都將是金融格局的中心。
What Causes Inflation in the United States
By Zaw Thiha Tun | September 02, 2015
Inflation affects everything around us, from basic necessities like housing, food, medical care and utilities to the cost of cosmetics and new automobiles. Furthermore, inflation can effortlessly deteriorate our savings. It makes the money saved today less valuable tomorrow, eroding our future purchasing power and even interfering with our ability to retire. In this article, we will examine the fundamental factors behind inflation in the United States including cost-push inflation, demand-pull inflation and the impact of consumer expectations on inflation.
Inflation: a Brief Introduction
But before we go any further, a brief primer on inflation and role of the price indices in measuring inflation is in order. Most economics textbooks define inflation as the sustained rise in the overall price-level of an economy. This means that money loses its purchasing power. The same amount of money can purchase fewer real goods and services into the future. Inflation is the opposite of deflation, which is a sustained decrease in the overall price level in an economy characterized by a negative inflation rate. The inflation rate is the percentage change in a price index. Central banks monitor the inflation rate closely, as it is the overriding force behind monetary policies. These are the monetary policies that impact the level of money supply and the availability of credit within an economy. Central banks of developed economies, including the Federal Reserve in the United States (the Fed), generally aim to keep the inflation rate around 2 percent per year.
Price Indices
As previously mentioned, the inflation rate is determined by the rate of change in a price index. The most cited and analyzed price index in the United States is the Consumer Price Index for All Urban Consumers, or CPI-U, which is released by the Bureau of Labor Statistics each month (the personal consumption expenditures (PCE) index covers all U.S. personal consumption). The Consumer Price Index for All Urban Consumers is a weighted basket of goods and services, ranging from food and beverage to education and recreation. A second, often-quoted price index is the producer price index (PPI), which includes things like fuels and farm products (meats and grains), chemical products and metals. The producer price index reports the price changes that affect domestic producers, and you can often see these prices changes being passed on to the consumers some time later in the Consumer Price Index.
An important distinction to make when measuring inflation rates is the difference between headline and core inflation. Headline inflation is inflation reflected in a price index by all goods and services in a country. Core inflation is headline inflation minus food and energy (excluded because food and energy are susceptible to short-term volatility). The latest Consumer Price Index for All Urban Consumers numbers released for the month of July 2015, rose a seasonally adjusted 0.1 percent from the prior month, and 0.2 percent year-over-year. When food and energy were factored out, core inflation rose a more substantial 1.8 percent year-over-year. This is still lower than the Fed's 2 percent target. (See also: The Consumer Price Index: A Friend To Investors.)
Cost-Push Inflation
Cost-push inflation is one of two main types of inflation within an economy. It refers to rising costs of production (usually in the form of wages), contributing to increasing pricing pressure. One of the signs of possible cost-push inflation can be seen in rising commodity prices, as commodities like oil and metals are major production inputs.
However, evidence has shown that the correlation between non-oil commodity prices and inflation has eroded since the 1980s. Wages are the single biggest expense for businesses. Analysts and policy makers currently see the labor market, through the unemployment rate, as the most important production input. As shortages in labor can create pressure to raise wages, it flows naturally that the lower the unemployment rate, the higher the possibility of labor shortages. Moreover, due to structural forces in the labor market (training inefficiencies, new and emerging industries, population changes and so on), the possibility of labor bottlenecks are created long before the unemployment rate ever reaches zero. The unemployment threshold, below which exists upwards wage pressure, is known as the non-accelerating rate of unemployment (NAIRU). (See also: What is the relationship between oil prices and inflation?)
Demand-Pull Inflation
While cost-push inflation is a supply-side issue, demand-pull inflation is inflation caused by high demand causing rising prices. Demand-pull inflation can be caused by factors such as the following:
Expansionary fiscal policy. By lowering taxes, governments can increase the amount of discretionary income for both business and consumers. Businesses may spend it on capital improvements, employee compensation or new hiring, among other things. Consumers may purchase more nonessential items. Furthermore, as the government stimulates the economy by increasing its spending, say by undertaking major infrastructure projects, the demand for goods and services will increase, leading to price increases.
Devaluation of the currency. Currency devaluation can lead to higher exports (as our good become suddenly less expensive and thus more attractive to foreign buyers) and this increases aggregate demand for our goods and services. Higher demand can lead to high prices. Currency devaluation can also result in lower imports (as foreign goods become suddenly more expensive to purchase with devalued dollars). This can increase cost-push inflationary pressures production inputs such as raw materials are imported.
Expansionary monetary policy. Through open market operations, central banks can increase the money supply and create a surplus of liquidity that can bring down the value of money vis-a-vis the price of goods. In other words, by expanding the money supply, the purchasing power of all the participants in an economy increases, leading to a rise in aggregate demand. If the supply of goods do not adjust with this excess demand, then there will upwards pressure on prices. As summarized by the monetarists--too much money chasing too few goods. Alternatively, governments can induce household and business borrowing by lowering the interest rate which will create demand for business expansionary investments and household goods. (See also: What factors cause shifts in aggregate demand? and Cost-Push Inflation Versus Demand-Pull Inflation.)
Inflationary Expectations
Aside from cost-push and demand-pull inflationary pressures, the impact of inflationary expectations on an economy cannot be overstated. Once inflation becomes prevalent enough in an economy, the expectation of further inflation becomes an overriding concern in the consciousness of consumers and businesses alike. These expectations then become a guiding principle behind the actions of these economic agents causing inflation to persist in an economy long after the initial shock has dissipated. We saw this phenomenon in the European and U.S. economies during the 1970s and early 1980s when high inflation rates persisted even after the economies were in a recessionary slump. The end result of high unemployment coupled with high inflation become known as stagflation, a dreaded condition.
Though inflationary expectations are difficult to observe outside of government surveys, one way to indirectly measure these expectations is through the spread between government-issued inflation-linked bonds, such as TIPS, and other government debt instruments that do not have inflation protection. For example, if the yield on a 10-year nominal bond is 4% and the yield on the 10 year inflation-linked bond is 2%, then we can infer the market has priced in a 2 percent rate of annual inflation over the next 10 years. Currently, as shown in the graph below, this spread is around 149 basis points.
The Bottom Line
Inflationary pressures in the United States can be attributed to three major factors: rising costs of inputs of production (cost-push), increases in aggregate demand (demand-pull) and consumer expectations of future inflation. Out of these three sources of inflation, demand-pull has been the most prominent in recent years, as governments around the world have pursued loose monetary policies in an effort to grow their economies. With the Federal Reserve set to raise short-term interest rates for the first time in nearly a decade, the direction of the global capital markets is contingent upon the U.S. inflation rate. Until the Fed takes a definitive stance, inflation will continue to take front and center stage on the financial landscape. (See also: The Chinese Devaluation of the Yuan.)
本文翻譯由兄弟財經提供
文章來源：http://www.investopedia.com/articles/investing/090215/what-causes-inflation-united-states.asp