Forecasting Forum

Showing posts with label Forecasting Forum.   Show all posts

Paper Tigers

From a new post by Adam M. Grossman:

“Economist Prakash Loungani has spent the better part of two decades researching the issue. In a 2001 study, Loungani evaluated experts’ ability to forecast recessions. His conclusion was blunt: “The record of failure to predict recessions is virtually unblemished.” In a follow-up study, looking at the 2008 financial crisis, Loungani’s findings were nearly identical. Economists uniformly failed to predict that global recession.

Perhaps Loungani’s study wasn’t comprehensive enough. What about all-star forecasters? Here the evidence is inevitably more anecdotal, but no more encouraging. Consider Abby Joseph Cohen, the recently-retired Goldman Sachs strategist. Her forecasts during the 1990s earned her the nickname “the Prophet of Wall Street.” But she later missed the two biggest meltdowns of her career: In 2000, when the dot-com bubble burst, Cohen predicted the market would rise. And she, along with virtually everybody else, missed the 2008 collapse.

A more recent example: Ray Dalio, the billionaire founder of hedge fund Bridgewater Associates, proclaimed in January of this year: “If you’re holding cash, you’re going to feel pretty stupid.” The year’s not over yet. But so far, cash has done materially better than the stock market, which is in negative territory.

The reality is that forecasting has always been difficult—and not just in the world of economics. Decca Records told the Beatles they have “no future in show business.” Walt Disney was once fired for “lacking imagination.” The list of incorrect predictions is long.

If forecasts are so error-prone, why do sensible organizations like Vanguard continue issuing them? In part, I believe it’s in response to investor demand: People want to know what’s going to happen and they believe experts can tell them. It’s just human nature. But now that you’ve seen the data, here’s my recommendation: Tune out anyone who approaches you with a crystal ball. Instead, situate yourself so the market’s short-term ups and downs don’t impact your ability to meet your financial goals—or to sleep at night.”

From a new post by Adam M. Grossman:

“Economist Prakash Loungani has spent the better part of two decades researching the issue. In a 2001 study, Loungani evaluated experts’ ability to forecast recessions. His conclusion was blunt: “The record of failure to predict recessions is virtually unblemished.” In a follow-up study, looking at the 2008 financial crisis, Loungani’s findings were nearly identical. Economists uniformly failed to predict that global recession.

Read the full article…

Posted by at 8:27 PM

Labels: Forecasting Forum

GDP predictions are reliable only in the short term

A new article from The Economist cites my paper:

“[…] economic forecasters project GDP growth of about 2% in 2020.”

“How much confidence should one have in these predictions? For the past 20 years The Economist has kept a database of projections by banks and consultancies for annual GDP growth. It now contains 100,000 forecasts across 15 rich countries. In general, they fared well over brief time periods, but got worse the further analysts peered into the future—a trend unsurprising in direction but humbling in magnitude. If a recession lurks beyond 2019, economists are unlikely to foresee it this far in advance.”

“The biggest errors occurred ahead of GDP contractions. The average projection 22 months before the end of a downturn year missed by 3.7 points, four times more than in other years. In part, this is because growth figures are “skewed”: economies usually expand slowly and steadily, but sometimes contract sharply. As a result, forecasters seeking to predict the most likely outcome expect growth. However, they adjust too slowly even once bad news arrives, says Prakash Loungani of the IMF. That suggests they are prone to “anchoring”—over-weighting previous expectations—or to “herding” (keeping their predictions near the consensus).”

“If forecasters displayed such biases consistently, an aggregator could beat the crowd by granting more weight to those with good records. But top performers rarely repeat their feats. When it comes to GDP, the best guide is the adage that prediction is difficult—especially about the future.”

A new article from The Economist cites my paper:

“[…] economic forecasters project GDP growth of about 2% in 2020.”

“How much confidence should one have in these predictions? For the past 20 years The Economist has kept a database of projections by banks and consultancies for annual GDP growth. It now contains 100,000 forecasts across 15 rich countries. In general, they fared well over brief time periods,

Read the full article…

Posted by at 8:12 PM

Labels: Forecasting Forum

GDP predictions are reliable only in the short term

From The Economist magazine:

They perform far better when forecasting growth years than downturns

SOME INVESTORS worry that America will face a recession in the next few years, after one of the longest expansions on record. Stock indices have fallen by 10% since early October. Yields on short-term government bonds exceed those of some longer-dated ones, often a harbinger of a downturn. Despite this, economic forecasters project GDP growth of about 2% in 2020.

How much confidence should one have in these predictions? For the past 20 years The Economist has kept a database of projections by banks and consultancies for annual GDP growth. It now contains 100,000 forecasts across 15 rich countries. In general, they fared well over brief time periods, but got worse the further analysts peered into the future—a trend unsurprising in direction but humbling in magnitude. If a recession lurks beyond 2019, economists are unlikely to foresee it this far in advance.

Economies are fiendishly complex, but forecasters usually predict short-term trajectories with reasonable accuracy. Projections made in early September for the year ending four months later missed the actual figure by an average of just 0.4 percentage points. Errors rose to 0.8 points when predicting one year out. But over longer horizons forecasts performed far worse. With 22 months of lead time, they misfired by 1.3 points on average—no better than repeating the previous year’s growth rate.

 

The biggest errors occurred ahead of GDP contractions. The average projection 22 months before the end of a downturn year missed by 3.7 points, four times more than in other years. In part, this is because growth figures are “skewed”: economies usually expand slowly and steadily, but sometimes contract sharply. As a result, forecasters seeking to predict the most likely outcome expect growth. However, they adjust too slowly even once bad news arrives, says Prakash Loungani of the IMF. That suggests they are prone to “anchoring”—over-weighting previous expectations—or to “herding” (keeping their predictions near the consensus).”

Read the full article here.

A separate article from Bloomberg says that:

Recession Signs Hard to Miss If Stock Message Is Taken Seriously

Prices bounce around, emotion obscures logic, signals appear and vanish. The reasons for treating equities as a poor barometer for the economy are many. Right now, that might be for the best.

Pools of gloom await anyone looking for a message in stocks. There’s the $3 trillion in value erased, the bloodbath in banks and the trouncing in transports. In wonkier circles, shrinking valuations and negative rolling returns have started to ring the recession bell. A relatively calm week in the Dow Jones Industrial Average just ended with a 495-point thud.

It’s a pastime on Wall Street these days to look at the carnage, add it all up, and announce that the market is wrong. But what if it’s not? After all, even if equities have predicted “nine of the last five recessions,” as the economist Paul Samuelson famously said, that’s a better record than a lot of humans.

(…)

Sure, markets overshoot, and sentiment gets carried away. Corrections like this one have occurred six other times since the bull market began in 2009. They all sparked growth scares. But none of them a recession.

“The market is wrong,” said Anik Sen, global head of equities at PineBridge Investments. “Clearly it has been a slowdown, but the slowdown can be very transitory in our view. At the end of day, there is enormous pent-up demand, whether it’s capex or technology spending. None of that has changed.”

Still, anyone heeding strategist calls shouldn’t forget Wall Street’s propensity to lean bullish. Over the past two decades when stocks suffered two bear markets, professional forecasters have never once predicted a down year. Economists don’t see one now, either. Eighty-nine surveyed by Bloomberg generate an average prediction of 2.6 percent growth in gross domestic product next year.

Meanwhile, a 2014 study by Prakash Loungani of the International Monetary Fund found that not one of 49 recessions suffered around the world in 2009 had been predicted by the consensus of economists a year earlier. Loungani previously reported that only two of the 60 recessions of the 1990s had been anticipated a year in advance.”

Read the full article here.

 

Also, see a related note on “There will be growth in the spring”: How well do economists predict turning points?

 

 

From The Economist magazine:

They perform far better when forecasting growth years than downturns

SOME INVESTORS worry that America will face a recession in the next few years, after one of the longest expansions on record. Stock indices have fallen by 10% since early October. Yields on short-term government bonds exceed those of some longer-dated ones, often a harbinger of a downturn. Despite this,

Read the full article…

Posted by at 1:37 PM

Labels: Forecasting Forum

Overfitting in Judgment-based Economic Forecasts: The Case of IMF Growth Projections

From a new IMF working paper:

“I regress real GDP growth rates on the IMF’s growth forecasts and find that IMF forecasts behave similarly to those generated by overfitted models, placing too much weight on observable predictors and underestimating the forces of mean reversion. I identify several such variables that explain forecasts well but are not predictors of actual growth. I show that, at long horizons, IMF forecasts are little better than a forecasting rule that uses no information other than the historical global sample average growth rate (i.e., a constant). Given the large noise component in forecasts, particularly at longer horizons, the paper calls into question the usefulness of judgment-based medium and long-run forecasts for policy analysis, including for debt sustainability assessments, and points to statistical methods to improve forecast accuracy by taking into account the risk of overfitting.”

From a new IMF working paper:

“I regress real GDP growth rates on the IMF’s growth forecasts and find that IMF forecasts behave similarly to those generated by overfitted models, placing too much weight on observable predictors and underestimating the forces of mean reversion. I identify several such variables that explain forecasts well but are not predictors of actual growth. I show that, at long horizons, IMF forecasts are little better than a forecasting rule that uses no information other than the historical global sample average growth rate (i.e.,

Read the full article…

Posted by at 5:48 PM

Labels: Forecasting Forum

Crowdsourcing Economic Forecasts

From a new working paper:

“Economic forecasts are often disseminated via a survey of professionals (i.e. “Consensus”). In this paper we compare and contrast the Consensus with a crowdsourced alternative wherein anyone may submit a forecast. We focus on U.S. Nonfarm Payrolls and find that, on average, Consensus is more accurate, but the best crowdsourced forecasters are superior to the best Consensus forecasters. We also find that information plays a key role. When the Consensus is uncertain and herds together, the crowdsourced forecasts appear to be more. Our findings provide evidence that crowdsourcing might provide a valuable supplement to traditional macroeconomic forecasts.”

From a new working paper:

“Economic forecasts are often disseminated via a survey of professionals (i.e. “Consensus”). In this paper we compare and contrast the Consensus with a crowdsourced alternative wherein anyone may submit a forecast. We focus on U.S. Nonfarm Payrolls and find that, on average, Consensus is more accurate, but the best crowdsourced forecasters are superior to the best Consensus forecasters. We also find that information plays a key role.

Read the full article…

Posted by at 5:39 PM

Labels: Forecasting Forum

Home Older Posts

Subscribe to: Posts