预料中的全球经济前景下调周期已经正式开始了。IMF最新发布的半年度《世界经济展望报告》传递了这一信息，且强化了几家知名私人预测机构早先所做的修正。

这次修正主要是因为乌克兰战争，其调整幅度颇大——2022年的世界经济增长率被大幅下调至3.6%，比IMF在6个月前预测的4.9%足足低了1.3个百分点。值得称道的是，IMF警告了这种情况即将出现，它此前在1月份发布的更新中已经向下修正了0.5个百分点。即便如此，回顾过去15年，这次修正在IMF每6个月一次的例行预测调整中也是第三大降幅。

2009年4月，随着全球金融危机蔓延，IMF将当年全球经济增长预期下调了4.3个百分点（从危机前预测的增长3%下调为直接收缩-1.3%）。当然了，由于2020年初新冠疫情暴发，IMF也将当年的增长预期下调了6.4个百分点（从疫情前预测的增长3.4%下调为直接收缩-3%）。在之前的这两个事例中，增长预测被大幅下调都预言了全球经济的急剧衰退，实际上，它们是现代史上最严重的两次衰退。

然而，IMF和其他大多数预测机构都不认为，当前的全球经济增长乏力会让全世界陷入绝对衰退。最新的《世界经济展望报告》声称96万亿美元的全球经济有望实现完美的软着陆。在最近将增长预期下调之后，目前对2022-23年的全球经济增长预测稳定在了3.6%，略高于1980年以来3.4%的平均水平。没有比这更平稳的着陆了。

但出于几个理由，这种想法很可能只是一厢情愿。

首先，预测者们在根据2021年的超高增速推断未来增长时过于乐观。根据1980年以来IMF的统计数据，2021年全球经济猛增6.1%，是记录中最强劲的反弹。但那是在2020年创下-3.1%这一最大记录跌幅之后出现的。正是疫情封控措施导致全球经济在2020年初几乎陷入停滞，重新开放，加上积极的货币和财政刺激，成为了所有反弹之母。

预测者和投资者都在按目前的趋势推断未来，所以重要的是要看清2020-21年的异常波动，如此才能清晰地读懂可供推断的趋势。在这两年里，全球GDP年均仅增长1.5%，远低于官方的全球衰退阙值（普遍认为是2.5%左右）。不必说，如果全球经济增长按照这种基本趋势进一步放缓，降幅超出软着陆的下行轨道，那么另一场全球性衰退就不再是遥不可及的。

质疑乐观预期的第二个理由是，中国所起的缓冲作用已被削弱。中国目前的经济增速远低于2010-19年时期的近8%。IMF的最新预测认为，中国2022-23年的年均增长率为4.75%，只及2009年全球金融危机后的半数多一点。实际上，当年中国的强劲增长是防止2012-16年全球再次陷入衰退的唯一因素。如今与当时一样，如果没有更具活力的中国经济，全球经济恢复的可能性很小。

这就是今天的风险。由于中国目前面临着三重冲击——新一波疫情封控、持续不断的去杠杆化压力（特别是房地产业动荡不安）、与俄罗斯的伙伴关系带来间接的战争损失——全球经济不可能再依靠中国获得恢复力。当然，这种切割是双向的。如果中国强化对俄罗斯的承诺，它将与这个“无条件的伙伴”一起陷入孤立。由于中国经济仍高度依赖世界其他地区，这可能是习近平主席面临的最大挑战。

第三，全球增长放缓周期与全球通胀和利率大幅上升周期并行。软着陆的支持者们对其后果不屑一顾，随着通胀飙升至40年来高点，他们甚至漫不经心地谈论起“峰顶通胀”（peak inflation）。这种独出心裁的想法认为，既然现在的情况如此糟糕，那么以后只会越来越好。

这种肤浅的算术论证没有抓住重点。由于3月份美国消费者价格指数飙升8.5%，到年底，这个关键的通胀晴雨表当然有可能大幅下降。但又能低到多少呢？低到足以把美联储从1970年代中期、1980年代初期以来最不负责的货币政策中拯救出来吗？

别指望了。尽管美联储现在语气强硬，但光说是没用的。金融市场预计未来6个月会累计加息约250个基点，到目前为止，美联储仅加息25个基点，或者说只兑现了10%。就算美联储如预期的那样，到今年11月将联邦基金利率提高到2.5%，名义政策利率也很可能远低于通胀率。

这意味着实际（经通胀调整的）联邦基金利率全年都将处在负区间，也即实际政策利率为负值的时期长达38个月，远超早先艾伦·格林斯潘、本·伯南克和珍妮特·耶伦治下的“适度宽松”时期的刺激力度。实际利率对于维持物价稳定和推动经济增长具有重要意义，在评估全球商业周期风险时，其底线是实际利率上升还有很长的路要走。

所有这些都凸显全球经济的下行风险正在形成。作为原华尔街的一名预测者，我非常理解大多数预测机构的心态，包括IMF那些才华横溢的专业人士，他们认为自己已经考虑了绝大多数可能的风险。在这种情况下，金融市场认同并且相信，由于各国央行仍在实行令人瞠目的宽松政策，一个具有通胀倾向的世界正以某种方式光荣地滑向软着陆。但这样的美好场景真的会在没有中国的情况下出现吗？做梦吧。

全文翻译自报业辛迪加（Project Syndicate），原文标题“Downside Risks to Global Growth”（2022）

The predictable downward revision cycle for the global economic outlook has officially begun. That's the message from the semi-annual World Economic Outlook just released by the International Monetary Fund, which reinforces earlier revisions from several prominent private forecasting teams.

The revision, largely in response to the war in Ukraine, is a big one – a sharp reduction in world economic growth to 3.6% for 2022, fully 1.3 percentage points below the IMF's global growth forecast of 4.9% made just six months earlier. To its credit, the IMF warned that this was coming, with an interim downward revision of 0.5 percentage point previously released in January. Even so, in looking back over the past 15 years, this is the third-largest cut in the IMF's regular six-month revision cycle.

In April 2009, as the global financial crisis (GFC) was unfolding, the IMF cut its global growth estimate for the year by 4.3 percentage points (taking its pre-crisis projection of 3% positive growth down to an outright contraction of -1.3%). And, of course, as the COVID-19 pandemic erupted in early 2020, the IMF slashed its growth estimate for the year by 6.4 percentage points (from a pre-pandemic projection of +3.4% to an outright contraction of -3%). In both of those earlier cases, the outsize forecast reductions foretold sharp global recessions – in fact, the two worst recessions in modern history.

Yet neither the IMF nor most other forecasters believe that the current shortfall in global growth will push the world into outright recession. The latest World Economic Outlook calls for a perfect soft landing in the $96 trillion global economy. Following the recent downward revision, global growth is now expected to settle comfortably into a 3.6% growth trajectory over 2022-23, which is fractionally above the 3.4% average since 1980. Landings don't get much smoother than that.

But that could well be wishful thinking, for several reasons.

For starters, forecasters were overly optimistic in extrapolating the sugar high of 2021 into the future. The 6.1% surge of global growth in 2021 was the sharpest rebound on record, according to IMF statistics dating back to 1980. But this followed the steepest plunge on record, a -3.1% collapse in 2020. Just as COVID lockdowns brought the bulk of the global economy to a virtual standstill in early 2020, reopening, in conjunction with aggressive monetary and fiscal stimulus, produced the mother of all snapbacks.

Forecasters, as well as investors, extrapolate current trends into the future, so it is important to look through the extraordinary volatility of 2020-21 to get a clean read on which trend to extrapolate. Over those two years, global GDP growth averaged just 1.5%, well below the official global recession threshold, widely thought to be around 2.5%. Needless to say, if world economic growth slows more toward that underlying trend than the soft-landing glide path, another global recession is hardly farfetched.

A second reason to doubt buoyant forecasts is that the China cushion has been deflated. China's economy is currently growing well below the nearly 8% pace recorded from 2010 to 2019. The latest IMF outlook puts average Chinese growth in 2022-23 at 4.75%, only a little more than half the post-GFC trend when strong Chinese growth was literally the only thing that prevented the world from relapsing into recession over the 2012-16 period. As was the case back then, global resilience without a more vigorous Chinese economy is highly unlikely.

That's the risk today. With China currently facing a trifecta of shocks – a new wave of COVID-19 lockdowns, the ongoing pressures of deleveraging (especially in its unstable property sector), and war-related collateral damage resulting from its ill-advised partnership with Russia – the world economy can no longer rely on China as a source of resilience. That, of course, cuts both ways. If China deepens its commitment to Russia, it will share in the isolation of its “unlimited partner.” For a Chinese economy that remains deeply reliant on the rest of the world, that could prove to be President Xi Jinping's greatest challenge.

Third, the downshift in the global growth cycle is being accompanied by a major upswing in the global inflation and interest-rate cycles. The soft-landing crowd is dismissive of the consequences. As inflation surges to 40-year highs, there is loose talk of “peak inflation” – the fanciful idea that it is so bad now that it can only get better from here.

This superficial arithmetic argument misses the point. With the US Consumer Price Index surging by 8.5% in March, there is of course an excellent chance that this key barometer of inflation will be considerably lower by year end. But how much lower? Low enough to rescue the US Federal Reserve from its most irresponsible monetary-policy gambit since the mid-1970s and early 1980s?

Don't count on it. While the Fed is now talking tough, talk is cheap. So far, it has delivered only 25 basis points, or just 10%, of the some 250 basis points of cumulative tightening that financial markets are expecting over the next six months. Even if the Fed moves as expected and boosts the federal funds rate to 2.5% by this November, the nominal policy rate is likely to be well below the inflation rate.

That means the real (inflation-adjusted) federal funds rate will remain in negative territory throughout the year, marking a 38-month period of negative real policy rates – far more stimulus than in earlier periods of über-accommodation under Alan Greenspan, Ben Bernanke, and Janet Yellen. Real interest rates matter in maintaining price stability and driving economic growth. When assessing risks to the global business cycle, the bottom line is that the upswing in real rates has much further to go.

All of this underscores the downside risks that are building in the global economy. As a recovering Wall Street forecaster, I empathize with the mindset of most forecasting teams, including the IMF's highly talented professionals, who believe that they have factored in most conceivable risks. In this case, financial markets concur, convinced that an inflation-prone world, with still jaw-droppingly accommodative central banks, is somehow gliding gloriously toward a soft landing for the ages. But is this already-rosy scenario really supposed to play out without China? Dream on.

Copyright: Project Syndicate, 2022.www.project-syndicate.org