歐央行總裁Mario Draghi週二為該行的年度央行研討會的開場演講《
Accompanying the economic recovery 》，令歐元升至今年新高。原因，正是以下一段話：
As the economy continues to recover, a constant policy stance will become more accommodative, and the central bank can accompany the recovery by adjusting the parameters of its policy instruments – not in order to tighten the policy stance, but to keep it broadly unchanged.
市場人士對呢番話的嘅解讀，係Draghi開始支持歐央行收水，例如縮減現行的資產購買計劃。在週三Bloomberg等主要媒體就報道，歐央行的知情人士出面解釋，Draghi的意思並非快將收水，而是希望強調歐央行的貨幣政策「中性」的取態，指出經濟好轉之餘都要繼續保留貨幣寬鬆政策。
本文的重點正正就係上面嗰句以外，Draghi的其他演講內容。
其實在這篇文章中，Draghi要討論的是通脹與整體需求（Aggregate Demand，AD）之間的關係，這當然有兩個層面：貨幣政策對AD的影響，及AD對通脹的影響。
文中，Draghi指出歐央行的寬鬆貨幣政策有效推高AD，例如自2015年開始推行資產購買計劃後歐元區的GDP增長3.6%，而就業人數錄得400萬增長。
Draghi指出，當經濟增長及就業情況轉強，經濟資源將得到更充份的應用，生產資源變得稀少，理應令工資及商品價格上升。歐央行目前的估算是歐元區的Unemployment Gap（即實際失業率與理論中的自然失業率之間的差距）會在未來兩年內消失，而這會為該區在2016至2019年間帶來1.7個百分點的通脹。
The unemployment gap – the difference between actual unemployment and the non-accelerating inflation rate of unemployment (NAIRU) – is narrowing and is forecast by the Commission to close within the next two years. Surveys of business capacity utilisation are now above their long-term average levels. And inflation is recovering. Between 2016 and 2019 we estimate that our monetary policy will have lifted inflation by 1.7 percentage points, cumulatively.
Yet the second leg of the inflation process – the transmission from rising demand to rising inflation – has been more subdued than in the past. How can this be explained?
但這由AD上升引發通脹的情況，近年明顯較預期的更弱，而Draghi就在文中以不少篇幅作討論。
第一個Draghi提出的解釋，是外圍經濟的短期因素（Temporary External Shocks）拖累通脹，一個明顯的例子就正是油價在2014至2015年的急跌。歐央行的研究指，在2015至16年間區內通脹較模型推算的為低，當中約三分二的差距可以用油價相關的因素解釋。
Inflation has indeed been subject to such shocks over recent years, most notably the oil and commodity price collapse in 2014-15. This not only depressed the cost of imported energy, but also lowered global producer prices more generally. ECB analysis suggests that the global component in the underperformance of euro area inflation in recent years was considerable. In 2015-16, around two thirds of the deviation of euro area headline inflation from a model-based mean can be accounted for by global shocks linked to oil prices.
Draghi指，雖然近年油價無再急跌，但早年的油價及商品價格大跌可能有延後效應，而相關的效應在油價無顯著反彈下可能更大，例如油價下跌會令生產時能源需求較高的服務及工業產品的價格下降；這亦令到核心通脹率都無法準確反映通脹的情況。
不過，歐央行的分析認為低油價是源於供應因素，長遠而言若區內的通脹預期不變，這應該不會改變通脹走向。
Global factors therefore do appear to be weighing on the path of inflation today. But our analysis suggests that the drivers of low oil prices at present are mainly supply factors, which a central bank can typically look through.[1] And even if supply factors affect the path of inflation for some time, with inflation expectations secure, they should not ultimately affect the inflation trend.
Part I 完。我未寫得完，所以應該會有Part II。
