Understanding Economic Forecasting

Almost every financial services firm has an extensive economic forecasting effort. It is usually part of a so-called top-down investment process, which starts with an outlook for the economy and monetary conditions, continues to the strongest industries, follows with detailed company study for stock selection and may include an overlay of technical analysis to provide a timing dimension. Some would add analysis of social and political conditions even before economic studies (see Politics and Investing).

Economic forecasts derive from models usually of the aggregate national or global economy, but sometimes of parts of those economies: particular industrial sectors, regions of the world or even single products or firms. Basic approaches to forecasting simply extrapolate the past; more sophisticated models attempt to understand the sources of past changes and build them into their forecasts. The latter requires knowledge of economic history and economic principles, though, even then, forecasting is by no means an exact science. But while the accuracy of economists' predictions is frequently a target of jokes, forecasting remains a popular pursuit.

Forecasts for the macroeconomy are published regularly by academic institutions, thinktanks, governments, central banks and international organizations like the OECD and the IMF. In these places, modeling can, to a certain extent, be conducted free of the constraint of producing quick and usable data on a daily basis. But in the investment world, forecasts are required to be done early and often. A relatively short-term outlook is normally the limit of their aspirations what will happen to interest rates within the next month? with decision-makers demanding rapid output that they hope will be directly relevant to their immediate problems.

Much of the output of financial market models is naturally closely guarded in the hope that it may bring advantage to its owners and their clients. But, at the same time, investment economists like to maintain a public profile for marketing purposes, and are often called on by the media to give their opinion on the latest macroeconomic developments. Their interpretations of economic data may give some clues as to how the financial markets will react, though more often than not, they are explaining why the markets have already reacted as they did. Invariably too, there are disagreements about what various indicators mean, depending on different beliefs about the economy, and whether the firm is taking an optimistic or pessimistic view of the markets.

Each month, the Economist polls a group of financial forecasters and calculates the average of their predictions for real GDP growth, consumer price inflation and current account balances in a variety of countries. More specialized services like Consensus Economics survey over three hundred economists each month and offer details on average private sector predictions.