|US Forecast: October 29, 2017|
2017:4--2022:4 (21 quarters)
The forecast is based on the national income and product accounts (NIPA) data that were released on October 27, 2017.
The Latest Version of the US Model
For purposes of this forecast the US model has been reestimated through 2017:3. These estimates and the complete specification of the model are presented in Appendix A: The US Model: October 29, 2017. A complete discussion of the version of the US model dated November 11, 2013, is in Macroeconometric Modeling. The current version differs from the November 11, 2013, version in the updated estimates and in the addition of the lagged value of housing wealth to the IHH equation, equation 4. Also, the assumption of first order serial correlation of the error terms has been dropped from equations 26 and 29, explaining CUR and INTG.
Unless otherwise noted, the flow variables in the model are presented in this memo and on the site at quarterly rates. This is a change from versions dated July 31, 2011, and back, where the flow variables were presented at annual rates. To convert quarterly rates to annual rates, just multiply by four.
Assumptions Behind the Forecast
The table below gives the growth rates that were assumed for the key exogenous variables in the model along with the actual growth rates between 1989:4 and 2007:4 (before the stimulus measures beginning in 2008).
Growth Rates (annual rates) Forecast Actual Assumptions 2007:4-1989:4 TRGHQ 2.0 4.0 COG 1.0 2.3 JG 1.0 -0.7 TRGSQ 2.0 5.3 TRSHQ 2.0 5.7 COS 1.0 3.9 JS 1.0 1.5 EX 11.0,10.0,10.0,9.0,8.0,7.0, 7.0,6.0,6.0,6.0,5.0... 6.0 PIM 0.0 1.2
The first seven variables are the main government policy variables in the model aside from tax rates. TRGHQ is real federal government transfer payments to households, COG is real federal government purchases of goods, JG is federal government civilian employment, TRGSQ is real federal government transfer payments to state and local governments, TRSHQ is real state and local government transfer payments to households, COS is real state and local government purchases of goods, JS is state and local government employment, EX is real exports, and PIM is the import price deflator. The notation for EX means that it was taken to grow at an annual rate of 11.0 percent in 2017.4, then 10.0, 10.0, 9.0, 8.0, 7.0, 7.0, 6.0, 6.0, and 6.0 in the following nine quarters, then 5.0 in each of the remaining quarters. This was done to have the U.S. trade deficit roughly constant over time, given the model's predictions of imports, IM.
All tax rates were taken to remain unchanged from their 2017:3 values.
No attempt has been made to guess what changes in tax rates might be made in the future. Nor has any attempt been made to guess what changes in government spending might be made in the future. The present forecast is a forecast conditional on no future tax changes and on the assumptions about government spending listed above. It is a base forecast from which experiments can be run regarding spending changes and tax changes.
The above assumptions regarding the state and local government variables result in roughly balanced budgets over time in the forecast.
No assumption is needed about monetary policy for the forecast because monetary policy is endogenous. Monetary policy is determined by equation 30, an estimated interest rate reaction function or rule.
Forecasts of selected variables are presented in the following: Forecasts of selected variables---html, Forecasts of selected variables---pdf file. If you want more detail, click "Solve current version" after "US Model," create a data set, and then go immediately to "Examine the results without solving the model." You can then examine any variable in the model.
Real GDP Growth and the Unemployment Rate: The forecast has real GDP growing at 2.7, 2.4, 2.2, and 2.1 percent in the next four quarters, respectively. It is then predicted to grow at about 2 percent for the rest of the horizon. (All growth rates in this memo are at annual rates.) The unemployment rate is 3.8 percent at the end of 2022.
Inflation: Inflation as measured by the growth of the GDP deflator (GDPD) is about 2.0 percent throughout the forecast period.
Monetary Policy: The estimated interest rate rule (equation 30) is predicting that the three month bill rate (RS) will gradually rise to 4.1 percent by the end of the forecast horizon as the unemployment rate falls.
Federal Government Budget: The nominal federal government budget deficit on a NIPA basis, variable -SGP, is predicted to rise gradually to $987.5 billion at the end of 2022. The federal government debt, variable -AG, is $19.8 trillion at the end of 2022, which is 82.9 percent of nominal GDP (variable AGZGDP in the model). This is up from 46.1 percent in 2007:1. Interest payments of the federal government, variable INTG, rise to $951.4 billion by the end of 2022, which is due to the increasing debt and rising interest rates. At the end of 2022 the ratio of INTG to GDP (variable INTGZGDP) is 4.0 percent.
U.S. Current Account: The deficit in the U.S. current account, variable -SR, is roughly constant throughout the period, which is by design in the choice of the EX values.
Comments on the Forecast and Possible Experiments to Run
The main message from the current forecast is that if there are no bad shocks, no tax rate changes, and government spending as assumed above, the economy grows at about 2 percent or a little more through 2022.
The assumption of no bad shocks, which is used for the forecast, means that stock prices, housing prices, and import prices grow at historically normal rates. There are no negative wealth shocks through falling stock prices and housing prices. Changes in asset prices like stock prices, housing prices, exchange rates, and oil prices are essentially unpredictable. One can use the US model to analyize the effects of asset price shocks, but the shocks themselves cannot be predicted. The best one can do in a forecast is to assume some historically average behavior of asset prices, which has been done here.
To examine the effects of asset price shocks, experiments can be run using the model in which stock prices (variable CG), housing prices (variable PSI14), and import prices (variable PIM) are changed. This allows one to examine the sensitivity of the forecast to changes in these values.
To review, oil price shocks and exchange rate shocks are handled through changes in PIM. Housing price changes are handled through changes in PSI14. Changes in PSI14 change PKH relative to PD and thus change housing wealth, PIH*KH. This affects consumption expenditures through the total wealth variable AA (equations 1, 2, and 3). It affects housing investment through the housing wealth variable AA2 (equation 4). Regarding the stock market, each change in the S&P 500 index of 10 points is a change in CG, the capital gains variable in the model, of about $100 billion. If you think that the S&P index will fall, say, 100 points, you should drop the equation for CG and change CG by about -$1,000 billion. See the discussion in Section 7.2 of The US Model Workbook, October 29, 2017. This will have a negative effect on real output growth because of a negative wealth effect.
Regarding the federal government spending variables, the key variables are TRGHQ and COG. The key personal income tax rate is D1G. The employee payroll tax rate is D4G. The corporate profit tax rate is D2G. Under President Trump and the Republican Congress, some of the exogenous federal government variables are likely to be condiserably different from what has been assumed for this forecast. Feel free to experiment with alternative assumptions, depending on what you think President Trump and the Congress will do.