Booms tend not to die of old age, and there are killers aplenty lurking in the shadows. Globally, policy is slowly but surely becoming less supportive of boom conditions. True, America only recently passed a budget-busting tax reform, which promises to swell its deficit and thus to boost American spending. But in most other rich countries government borrowing is flat to falling. Across much of the emerging world, too, deficits are expected to shrink in coming years. China’s government is trying to rein in the credit-dependency of its economy, with some success.

經(jīng)濟(jì)繁榮一般并不會因?yàn)楸３謺r(shí)間過長而消退，在暗處潛伏著許多的殺手。從全球范圍而言，經(jīng)濟(jì)政策正在緩慢卻又堅(jiān)定地改變支持經(jīng)濟(jì)繁榮的方針。確實(shí)，美國最近通過了一項(xiàng)會耗盡預(yù)算的稅改方案，這個方案將要增加赤字來刺激美國的消費(fèi)。在其他富裕國家，政府借貸正在平緩下降。其他許多國家也是同樣，赤字在可預(yù)見的未來幾年會下降。中國政府正在對其信用依賴性進(jìn)行控制，并取得了一些成果。

Central banks are pitiless executioners of long-lived booms, and monetary policy has shifted. America’s Federal Reserve has slowly been raising its benchmark interest rate since late 2015. The Bank of England followed suit in 2017 and is expected to continue to increase interest rates slowly over the next few years. The European Central Bank (ecb) will probably conclude its stimulative bond-buying in December and may begin to raise its benchmark rate in late 2019. Global financial conditions, though still fairly relaxed, have become slightly less so recently. Most central banks have become less concerned about economic weakness and more worried about inflation. If they overdo their reaction, they could slow down the global economy more than intended.

中央銀行是長期經(jīng)濟(jì)繁榮的無情終結(jié)者，貨幣政策也同樣已經(jīng)發(fā)生變化。美國聯(lián)邦儲備系統(tǒng)自 2015 年以來緩慢的增加其基準(zhǔn)利率。英格蘭銀行在 2017 年跟進(jìn)，并且在預(yù)期的未來幾年內(nèi)持續(xù)緩慢增加其基準(zhǔn)利率。歐洲中央銀行可能在十二月終結(jié)其刺激債權(quán)購買的政策，并可能在 2019 年晚些時(shí)候開始增加基準(zhǔn)利率。全球經(jīng)濟(jì)環(huán)境，雖然仍較為寬松，但在最近已經(jīng)開始慢慢縮進(jìn)。大多數(shù)中央銀行開始不再擔(dān)憂經(jīng)濟(jì)下滑而開始關(guān)心通脹。而如果這些銀行過分反映，就可能比預(yù)期的更多的減慢全球經(jīng)濟(jì)發(fā)展。

America’s Fed, in particular, is treading a difficult path. Over the past few decades economic and financial cycles in the global economy have become more closely connected. Some economists reckon that the link remains loose. Eugenio Cerutti of the imf, Stijn Claessens of the Bank for International Settlements (bis) and Andrew Rose of the University of California, Berkeley reckon that global financial factors explain no more than a quarter of the movement of capital across borders. Others disagree. Hélène Rey, of the London Business School, links the global financial cycle to worldwide swings in appetite for risk, which is in turn governed by the stance of American monetary policy. òscar Jordà and Alan Taylor, of the University of California, Davis and colleagues have found cross-border wobbling in financial variables such as equity prices is at its most synchronised for more than a century.

尤其是美國聯(lián)邦儲備系統(tǒng)，正行走在艱難的道路之上。在過去的幾十年中，全球經(jīng)濟(jì)和金融結(jié)合變得越來越緊密。有些經(jīng)濟(jì)學(xué)家認(rèn)為這種聯(lián)結(jié)仍然較為寬松。國際貨幣基金組織的 Eugenio Cerutti ，國際清算銀行的 Stijn Claessens ，加州大學(xué)伯克利分校的 Andrew Rose 認(rèn)為全球經(jīng)濟(jì)因素僅僅能解釋不超過四分之一的國家間資本運(yùn)作。而其他經(jīng)濟(jì)學(xué)家并不同意。倫敦商學(xué)院的 Hélène Rey 認(rèn)為，全球經(jīng)濟(jì)周期與世界范圍內(nèi)對于風(fēng)險(xiǎn)的渴望，而這又是由美國貨幣政策所決定。加州大學(xué)的 òscar Jordà 和 Alan Taylor 發(fā)現(xiàn)金融狀況在不同國家間漲跌，諸如股本價(jià)格，在一個多世紀(jì)以來都是高度一致的。