通縮也許並不可怕 風險與機遇並存

Our perception that inflation is the normal condition is no more than a reflection of the experience of people alive today. In 1913, unlike now, a pound or a dollar would have bought the same goods as a century earlier. The longest semi-official price series we have reports a 140 fold rise in prices in the UK since 1750 — but even then all the increase up to 1938 is accounted for by inflation during the Napoleonic and first world wars. Indeed, while the price level roughly doubled during both these episodes, it fell slightly over the rest of the period.

我們對於通脹是常態的觀念，只是反映了當今在世的人們的經驗。不同於現在，1913年時1英鎊或1美元能夠買到與一個世紀前同樣的商品。我們擁有的最長的半官方價格序列顯示，自1750年以來英國物價上漲了140倍，但即便如此，截至1938年的所有上漲均可歸因於拿破崙戰爭以及第一次世界大戰期間的通脹。的確，儘管物價水平在這兩次戰爭期間大致都翻了一番，但在其他時期略有下降。

This historical perspective may offer a partial antidote to the fears of investors over the arrival of deflation in Europe, where a euro today buys more than a year ago. But there are other reasons not to panic. For one, there is no qualitative difference between an economy in which prices are rising slightly and one in which prices are falling slightly. Unlike water, liquid at temperatures above 0C and solid below, the consumer price index is a complex statistical construct not a physical fact. You can see and feel the difference between ice and water, and you can skate on one but not the other. Similarly, with a commodity such as petrol, you can tell whether the price at the pump is rising or falling because petrol is a homogeneous product that changes little over time.

這一歷史視角可能在一定程度上緩解投資者對於通縮降臨歐洲的擔憂，如今1歐元在歐洲的購買力已超過1年前的水平。但還有其他理由讓人們不必恐慌。首先，物價緩慢上漲與物價緩慢下跌的兩個經濟體之間沒有本質區別。與水（0攝氏度以上爲液體，以下爲固體）不同，消費者價格指數(CPI)是一個複雜的統計模型，而非物理事實。你可以看到並感覺到冰與水的不同，而且冰上可以滑行，水上不行。同樣地，對於汽油這類商品，你可以在加油站看出其價格是升還是降，因爲汽油是一種隨時間推移變化很小的同質產品。

But what has been happening with cars, or smartphones, or medical services? In the CPI, the price component for cars comprises the sticker price adjusted for changes in quality. Such quality adjustment is subjective — and, it is generally conceded, too low. So we could have been experiencing deflation for years without realising it.

但是，汽車、智能手機或是醫療服務發生了什麼變化呢？在消費者價格指數中，汽車價格構成中包括根據品質變化而調整的標牌價格。此類品質調整是主觀的，而且被普遍認爲太低。因此，我們可能多年經歷通縮，但對它毫無察覺。

Moreover, the surface of a pond will be cold enough to skate on when the average temperature of the whole pond (ice on the surface and water beneath) is well above zero. With a good deal of effort you could compute the average temperature of the entire contents of the pond. But the answer will not tell you whether it is safe to skate.

此外，當整個水池（表面是冰，下面爲水）的平均氣溫高於0攝氏度時，水池表面的溫度可能冷到可以滑行。你如果煞費苦心，可以計算出水池全部水體的平均溫度。但這一答案不會告訴你在結冰的表面滑冰是否安全。

The central point is that the significance of a fall in a price index depends on the causes of that fall. The declining price level in the second half of the 19th century was the result of rising manufacturing productivity and the opening up of new lands, particularly in North America. Global grain prices tumbled from the end of the US civil war until the 1890s. This raised real industrial incomes in more advanced economies but also reduced agricultural rents — the beginning of the end for the Old World’s landed aristocracy. The 19th century technological developments and shifts in global trade patterns have obvious parallels today in the development of a digital economy and the rise of China, which have similarly contributed to the fall in the inflation rate since 1980.

問題的核心在於，價格指數下降的重要性取決於下降的原因。19世紀後半葉物價水平的下跌是製造業生產率提高以及新增開墾土地（尤其是在北美）的結果。全球穀物價格從美國內戰結束至1890年代一直在下跌。這既提高了更發達經濟體的實際工業收入，也減少了農業租金——舊世界的土地貴族由此開始走向衰亡。19世紀的科技進步和全球貿易格局變化，與當今數字經濟的發展以及中國的崛起明顯相似，後兩者促進了自1980年以來通脹率的下降。

On the other hand the deflation, and the associated depression and social strife, that Britain experienced between the world wars was largely the result of a misguided attempt to restore the 1914 exchange rate against the dollar. Prices in Britain fell steadily after 1920 until President Franklin Roosevelt finally wrecked the gold standard at the London Conference on exchange rate stabilisation in 1933.

另一方面，英國在兩次世界大戰間隔期間所經歷的通縮（以及伴隨而來的蕭條和社會衝突），主要是一項旨在恢復1914年時英鎊/美元匯率的誤入歧途的嘗試所致。英國的物價在1920之後不斷下降，直至美國總統富蘭克林•羅斯福(Franklin Roosevelt)最終在1933年討論匯率穩定的倫敦會議上破壞了金本位制。

This dismal economic policy and economic performance finds modern parallels, too — here, in the travails of the eurozone. Falling prices have often been associated with economic transformations or recessions; but, contrary to the fears and hopes of investors, price deflation is the effect rather than the cause.

這種糟糕的經濟政策和經濟表現在現代也有影子，歐元區的艱難處境就是一例。物價下跌往往伴隨着經濟轉型或衰退；但與投資者的擔憂和希望相反，物價下跌是結果，而非原因。

The development that is tipping western economies into “deflation”, defined as a negative year-on-year change in CPI, is the fall in energy prices, which is good news for importing countries.

導致西方經濟體進入“通縮”（消費者價格指數同比負增長）的事態是能源價格的下降，但這對能源進口國是個好消息。

Raised body temperature might be a sign of fever or the result of a relaxing hot bath: it is wise to determine which it is before you start to worry, far less prescribe remedies.

體溫升高可能是發燒的徵兆，也可能是洗了一個讓人放鬆的熱水澡的結果：在開始擔憂之前先確定原因是明智的，而急着開處方補救是不可取的。