FRB: G.17 Release-- Industrial Production and Capacity Utilization

Federal Reserve Seasonal Factors for Domestic Auto and Truck Production

Seasonal factors for auto and truck production were revised in November 2008 and extended through September 2009. These factors were based on production data through September 2008 and were revised back to May 2008. Seasonal factors will next revise at the time of the annual revision to the index of industrial production, currently planned for the end of March 2009.

Monthly figures for motor vehicle assemblies in millions of units at an annual rate are published in Table 3 of the G.17 release. The formula for seasonally adjusted annual rates (SAAR) of auto and truck production (in millions of units) for each month is

    

       SAAR = ((NSA data in units/1,000,000) * 12)/(SF * .01).

The not seasonally adjusted (NSA) data are obtained from Ward’s Communications, and the seasonal factors (SF), which contain adjustments for holiday and length-of-month effects as well as normal seasonal variation, are shown in the table below under "Regular Seasonal Factors."

The table below also shows a set of seasonal factors on a weekday average basis in the columns under "Weekday-basis Seasonal Factors"; the number of production days in a month, or weekdays, is shown separately. Using this information, the formula for seasonally adjusted annual rates of auto and truck production (in millions of units) for each month is

    

       SAAR = ((NSA data in units/1,000,000) * 260)/(weekdays * SFW * .01).

Multiplying by 260, the average number of weekdays in a year, converts the weekday average production to an annual production rate. This formula reduces to

    

       SAAR = (NSA data in units * .026) / (weekdays * SFW).

A comma-delimited text file containing these seasonal factors is available for download here.

Monthly Seasonal Factors for Domestic Auto and Truck Production
	Regular Seasonal Factors			Weekday-basis Seasonal Factors
	Autos	Total Trucks	Light Trucks	Autos	Total Trucks	Light Trucks	Weekdays
	Autos	Total Trucks	Light Trucks	Autos	Total Trucks	Light Trucks	Weekdays
Jan-1998	89.68	89.71	89.99	88.32	88.35	88.63	22
Feb-1998	99.57	101.25	101.53	107.87	109.69	109.99	20
Mar-1998	113.55	114.34	114.62	111.83	112.61	112.88	22
Apr-1998	105.41	106.46	106.32	103.81	104.84	104.71	22
May-1998	105.15	105.39	105.56	108.48	108.73	108.92	21
Jun-1998	102.70	101.53	101.32	101.15	99.99	99.79	22
Jul-1998	74.24	67.78	66.23	69.94	63.86	62.39	23
Aug-1998	99.62	95.41	95.11	102.78	98.44	98.13	21
Sep-1998	104.04	110.29	110.77	102.46	108.61	109.09	22
Oct-1998	112.53	113.29	113.41	110.82	111.57	111.69	22
Nov-1998	93.96	93.48	93.77	96.94	96.44	96.75	21
Dec-1998	88.57	89.47	89.50	83.44	84.28	84.31	23
Jan-1999	89.82	89.60	89.95	92.67	92.44	92.80	21
Feb-1999	99.37	101.16	101.44	107.65	109.59	109.90	20
Mar-1999	118.59	119.54	119.83	111.71	112.61	112.89	23
Apr-1999	105.14	106.22	106.09	103.55	104.61	104.48	22
May-1999	104.81	105.12	105.25	108.14	108.45	108.59	21
Jun-1999	112.87	108.01	107.50	111.16	106.38	105.87	22
Jul-1999	63.77	61.58	60.30	62.80	60.64	59.38	22
Aug-1999	105.84	104.65	104.59	104.23	103.06	103.00	22
Sep-1999	105.11	107.02	107.29	103.51	105.40	105.67	22
Oct-1999	106.87	107.73	107.87	110.26	111.15	111.29	21
Nov-1999	99.80	99.20	99.53	98.29	97.70	98.03	22
Dec-1999	87.96	89.44	89.50	82.86	84.25	84.31	23
Jan-2000	95.03	94.28	94.72	98.05	97.27	97.72	21
Feb-2000	103.92	105.88	106.18	107.22	109.24	109.55	21
Mar-2000	118.33	119.86	120.16	111.47	112.91	113.19	23
Apr-2000	94.43	95.23	95.10	102.30	103.16	103.03	20
May-2000	110.03	110.29	110.37	103.65	103.89	103.98	23
Jun-2000	112.83	110.70	110.31	111.12	109.02	108.64	22
Jul-2000	61.88	60.68	59.54	63.84	62.60	61.43	21
Aug-2000	110.38	109.30	109.18	103.98	102.96	102.85	23
Sep-2000	100.07	98.30	98.35	103.24	101.42	101.47	21
Oct-2000	111.55	112.79	112.95	109.86	111.08	111.24	22
Nov-2000	100.32	99.77	100.13	98.80	98.26	98.62	22
Dec-2000	82.33	84.08	84.15	84.95	86.75	86.82	21
Jan-2001	100.29	98.83	99.34	94.47	93.10	93.58	23
Feb-2001	98.56	100.38	100.67	106.77	108.75	109.05	20
Mar-2001	112.72	114.67	114.96	111.02	112.94	113.22	22
Apr-2001	99.63	100.37	100.23	102.79	103.55	103.41	21
May-2001	115.29	115.65	115.71	108.61	108.94	109.00	23
Jun-2001	107.73	105.20	104.77	111.15	108.54	108.10	21
Jul-2001	62.25	60.87	59.46	61.30	59.95	58.56	22
Aug-2001	111.56	110.43	110.33	105.09	104.03	103.94	23
Sep-2001	97.24	95.77	95.97	105.35	103.75	103.96	20
Oct-2001	116.35	117.86	118.05	109.60	111.02	111.21	23
Nov-2001	100.61	100.23	100.62	99.08	98.71	99.10	22
Dec-2001	76.88	78.64	78.72	79.32	81.14	81.22	21
Jan-2002	100.62	98.77	99.33	94.79	93.05	93.57	23
Feb-2002	98.24	99.94	100.22	106.43	108.27	108.57	20
Mar-2002	102.15	104.20	104.46	105.39	107.51	107.77	21
Apr-2002	110.13	110.80	110.65	108.46	109.12	108.98	22
May-2002	115.28	115.69	115.73	108.59	108.99	109.02	23
Jun-2002	102.68	99.87	99.43	111.24	108.20	107.72	20
Jul-2002	69.81	65.61	64.19	65.76	61.80	60.47	23
Aug-2002	102.17	102.88	102.73	100.63	101.32	101.18	22
Sep-2002	100.62	100.42	100.59	103.81	103.60	103.78	21
Oct-2002	116.13	117.58	117.80	109.40	110.76	110.97	23
Nov-2002	90.35	89.91	90.29	93.22	92.77	93.15	21
Dec-2002	76.57	78.55	78.62	75.41	77.36	77.43	22
Jan-2003	101.10	98.43	98.54	95.24	92.73	92.83	23
Feb-2003	100.21	100.72	100.96	108.56	109.11	109.38	20
Mar-2003	108.21	109.43	109.74	111.65	112.91	113.22	21
Apr-2003	105.69	104.77	104.61	104.09	103.19	103.02	22
May-2003	108.42	109.25	109.29	106.78	107.60	107.63	22
Jun-2003	102.52	101.53	101.27	105.77	104.75	104.49	21
Jul-2003	73.34	67.32	65.99	69.09	63.42	62.17	23
Aug-2003	102.05	101.04	101.18	105.29	104.25	104.39	21
Sep-2003	102.62	104.54	104.65	101.07	102.96	103.06	22
Oct-2003	114.67	118.65	118.87	108.02	111.77	111.98	23
Nov-2003	90.88	91.06	91.31	98.45	98.64	98.92	20
Dec-2003	85.47	88.54	88.77	80.51	83.40	83.62	23
Jan-2004	91.81	89.05	89.11	90.41	87.70	87.76	22
Feb-2004	100.68	100.74	100.98	109.07	109.13	109.40	20
Mar-2004	118.73	119.96	120.29	111.85	113.00	113.32	23
Apr-2004	105.66	104.49	104.33	104.06	102.90	102.75	22
May-2004	101.14	101.74	101.74	104.35	104.97	104.97	21
Jun-2004	110.83	110.21	109.96	109.15	108.54	108.30	22
Jul-2004	68.54	63.75	62.40	67.50	62.78	61.45	22
Aug-2004	105.40	104.19	104.23	103.81	102.61	102.65	22
Sep-2004	105.91	107.52	107.81	104.30	105.89	106.17	22
Oct-2004	104.15	108.12	108.31	107.46	111.55	111.75	21
Nov-2004	94.71	94.79	95.07	93.27	93.35	93.63	22
Dec-2004	85.22	88.44	88.69	80.28	83.31	83.55	23
Jan-2005	97.19	92.43	92.39	100.28	95.36	95.32	21
Feb-2005	100.47	100.85	101.11	108.85	109.26	109.54	20
Mar-2005	107.22	109.44	109.82	101.00	103.09	103.45	23
Apr-2005	110.08	110.62	110.64	113.57	114.13	114.15	21
May-2005	104.63	106.94	107.10	103.04	105.32	105.47	22
Jun-2005	111.61	111.03	110.92	109.92	109.35	109.24	22
Jul-2005	64.32	60.43	59.11	66.36	62.35	60.99	21
Aug-2005	112.89	111.24	111.47	106.34	104.80	105.01	23
Sep-2005	104.79	105.94	106.06	103.20	104.33	104.46	22
Oct-2005	104.33	106.06	105.99	107.64	109.42	109.36	21
Nov-2005	94.92	94.90	95.12	93.48	93.46	93.67	22
Dec-2005	86.37	88.75	88.90	85.06	87.41	87.56	22
Jan-2006	97.65	92.15	92.04	96.17	90.75	90.65	22
Feb-2006	100.80	101.27	101.55	109.20	109.71	110.01	20
Mar-2006	117.36	119.87	120.31	110.56	112.92	113.33	23
Apr-2006	94.29	94.76	94.77	102.14	102.66	102.67	20
May-2006	110.62	113.41	113.58	104.20	106.83	107.00	23
Jun-2006	111.40	111.28	111.23	109.72	109.60	109.55	22
Jul-2006	65.80	60.34	59.03	67.89	62.25	60.91	21
Aug-2006	112.12	112.54	112.89	105.62	106.02	106.34	23
Sep-2006	99.64	100.56	100.61	102.80	103.76	103.80	21
Oct-2006	109.27	111.11	111.00	107.62	109.43	109.32	22
Nov-2006	94.81	94.75	94.95	93.38	93.32	93.51	22
Dec-2006	81.27	83.36	83.51	83.85	86.01	86.16	21
Jan-2007	102.88	96.41	96.19	96.91	90.82	90.62	23
Feb-2007	101.03	101.65	101.95	109.44	110.12	110.44	20
Mar-2007	112.23	114.65	115.10	110.53	112.91	113.36	22
Apr-2007	99.57	100.01	100.03	102.73	103.19	103.20	21
May-2007	110.01	113.22	113.41	103.64	106.66	106.84	23
Jun-2007	106.08	106.53	106.54	109.45	109.91	109.92	21
Jul-2007	71.83	65.65	64.37	70.74	64.65	63.39	22
Aug-2007	110.06	111.07	111.36	103.68	104.63	104.91	23
Sep-2007	94.78	95.13	95.15	102.67	103.05	103.08	20
Oct-2007	114.24	116.30	116.17	107.62	109.56	109.43	23
Nov-2007	99.84	99.97	100.16	98.33	98.46	98.64	22
Dec-2007	77.31	78.18	78.25	79.77	80.66	80.74	21
Jan-2008	104.03	95.17	94.66	98.00	89.65	89.17	23
Feb-2008	106.65	106.04	106.23	110.03	109.40	109.60	21
Mar-2008	98.85	98.96	99.11	101.98	102.10	102.26	21
Apr-2008	112.52	115.70	115.97	110.81	113.95	114.21	22
May-2008	100.39	107.43	107.49	98.87	105.80	105.86	22
Jun-2008	103.56	108.44	108.84	106.85	111.88	112.30	21
Jul-2008	74.41	68.67	67.39	70.10	64.69	63.49	23
Aug-2008	102.46	98.79	99.07	105.72	101.92	102.21	21
Sep-2008	105.26	104.64	104.62	103.66	103.05	103.04	22
Oct-2008	115.65	113.80	113.64	108.95	107.20	107.05	23
Nov-2008	84.66	84.25	84.45	91.72	91.27	91.48	20
Dec-2008	87.94	88.75	88.90	82.84	83.61	83.74	23
Jan-2009	94.30	86.19	85.82	92.87	84.89	84.52	22
Feb-2009	101.13	102.37	102.70	109.56	110.90	111.25	20
Mar-2009	114.32	115.52	115.89	112.59	113.77	114.14	22
Apr-2009	101.43	106.43	106.29	99.89	104.81	104.68	22
May-2009	94.94	102.19	102.25	97.96	105.44	105.49	21
Jun-2009	108.24	113.99	114.50	106.60	112.26	112.76	22
Jul-2009	76.00	68.29	67.01	71.59	64.33	63.12	23
Aug-2009	102.59	100.26	100.60	105.84	103.44	103.80	21
Sep-2009	103.89	102.99	102.89	102.32	101.43	101.33	22

Industrial Output Section
Division of Research and Statistics
Board of Governors of the Federal Reserve System
Washington D.C. 20551

Statistical releases