Prices in the West Region, as measured by the Consumer Price Index for All Urban Consumers (CPI-U), inched up 0.1 percent in December, the U.S. Bureau of Labor Statistics reported today. (See table A.) The December increase was influenced by higher prices for shelter and food. (Data in this report are not seasonally adjusted. Accordingly, month-to-month changes may reflect seasonal influences.)

Over the last 12 months, the CPI-U rose 3.1 percent. (See chart 1 and table A.) Energy prices advanced 8.4 percent, largely the result of an increase in the price of gasoline. The index for all items less food and energy rose 2.9 percent over the year. (See table 1.)

Food

Food prices advanced 0.4 percent for the month of December. (See table 1.) Prices for food at home rose 0.5 percent, while prices for food away from home were virtually unchanged for the same period.

Over the year, food prices rose 1.9 percent. Prices for food away from home increased 3.6 percent since a year ago, and prices for food at home increased 0.6 percent.

Energy

The energy index decreased 1.1 percent over the month. The decrease was mainly due to lower prices for gasoline (-2.5 percent). Prices for natural gas service advanced 1.4 percent, and prices for electricity advanced 0.4 percent for the same period.

Energy prices advanced 8.4 percent over the year, largely due to higher prices for gasoline (15.4 percent). Prices paid for electricity rose 1.9 percent, but prices for natural gas service declined 2.3 percent during the past year.

All items less food and energy

The index for all items less food and energy inched up 0.1 percent in December. Higher prices for household furnishings and operations (0.8 percent), new and used motor vehicles (0.5 percent), and shelter (0.4 percent) were partially offset by lower prices for apparel (-3.8 percent) and other goods and services (-0.5 percent).

Over the year, the index for all items less food and energy rose 2.9 percent. Components contributing to the increase included shelter (4.5 percent) and medical care (2.1 percent). Partly offsetting the increases were price declines in apparel (-1.3 percent) and education and communication (-0.6 percent).

Table A. West Region CPI-U monthly and annual percent changes (not seasonally adjusted)

Month	2012		2013		2014		2015		2016		2017
	Monthly	Annual	Monthly	Annual	Monthly	Annual	Monthly	Annual	Monthly	Annual	Monthly	Annual
January	0.4	2.6	0.3	1.7	0.3	1.7	-0.3	0.7	0.5	2.6	0.5	2.5
February	0.4	2.5	0.8	2.0	0.4	1.3	0.6	0.9	0.1	2.1	0.6	3.0
March	0.9	2.4	0.4	1.5	0.6	1.5	0.8	1.1	0.2	1.5	0.3	3.1
April	0.2	2.1	0.0	1.3	0.3	1.8	0.3	1.0	0.5	1.8	0.3	2.9
May	0.2	2.0	0.2	1.3	0.6	2.3	0.8	1.2	0.5	1.5	0.2	2.6
June	-0.2	2.0	0.1	1.5	0.1	2.3	0.0	1.1	0.2	1.6	0.0	2.5
July	-0.3	1.8	0.0	1.9	0.1	2.3	0.3	1.3	0.1	1.4	0.1	2.5
August	0.5	2.1	0.1	1.5	-0.1	2.1	-0.1	1.3	0.0	1.5	0.2	2.7
September	0.5	2.2	0.2	1.3	0.1	2.0	-0.2	1.0	0.3	2.0	0.5	2.9
October	0.4	2.5	-0.1	0.9	-0.1	2.0	0.0	1.1	0.3	2.3	0.3	2.9
November	-0.7	1.9	-0.4	1.3	-0.6	1.7	-0.2	1.5	-0.2	2.3	0.0	3.1
December	-0.5	1.7	0.0	1.8	-0.5	1.3	-0.1	1.8	0.0	2.5	0.1	3.1

The January 2018 Consumer Price Index for the West Region is scheduled to be released on February 14, 2018.

Technical Note

The Consumer Price Index (CPI) is a measure of the average change in prices over time in a fixed market basket of goods and services. The Bureau of Labor Statistics publishes CPIs for two population groups: (1) a CPI for All Urban Consumers (CPI-U) which covers approximately 89 percent of the total population and (2) a CPI for Urban Wage Earners and Clerical Workers (CPI-W) which covers 28 percent of the total population. The CPI-U includes, in addition to wage earners and clerical workers, groups such as professional, managerial, and technical workers, the self-employed, short-term workers, the unemployed, and retirees and others not in the labor force.

The CPI is based on prices of food, clothing, shelter, and fuels, transportation fares, charges for doctors' and dentists' services, drugs, and the other goods and services that people buy for day-to-day living. Each month, prices are collected in 87 urban areas across the country from about 6,000 housing units and approximately 24,000 retail establishments--department stores, supermarkets, hospitals, filling stations, and other types of stores and service establishments. All taxes directly associated with the purchase and use of items are included in the index.

The index measures price changes from a designated reference date (1982-84) that equals 100.0. An increase of 16.5 percent, for example, is shown as 116.5. This change can also be expressed in dollars as follows: the price of a base period "market basket" of goods and services in the CPI has risen from $10 in 1982-84 to $11.65. For further details see the CPI home page on the Internet at www.bls.gov/cpi and the BLS Handbook of Methods, Chapter 17, The Consumer Price Index, available on the Internet at www.bls.gov/opub/hom/cpi/.

In calculating the index, price changes for the various items in each location are averaged together with weights that represent their importance in the spending of the appropriate population group. Local data are then combined to obtain a U.S. city average. Because the sample size of a local area is smaller, the local area index is subject to substantially more sampling and other measurement error than the national index. In addition, local indexes are not adjusted for seasonal influences. As a result, local area indexes show greater volatility than the national index, although their long-term trends are quite similar. NOTE: Area indexes do not measure differences in the level of prices between cities; they only measure the average change in prices for each area since the base period.

The West Region covered in this release is comprised of the following thirteen states: Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming.

Information in this release will be made available to sensory impaired individuals upon request. Voice phone: (202) 691-5200; Federal Relay Service: (800) 877-8339.

Table 1. Consumer Price Index for All Urban Consumers (CPI-U): Indexes and percent changes for selected periods

West (1982-84=100 unless otherwise noted)

Item and Group	Indexes			Percent change from-
	Oct. 2017	Nov. 2017	Dec. 2017	Dec. 2016	Oct. 2017	Nov. 2017
Expenditure category
All Items	257.223	257.126	257.347	3.1	0.0	0.1
All items (December 1977=100)	415.786	415.629	415.987
Food and beverages	255.751	255.463	256.376	1.9	0.2	0.4
Food	255.590	255.236	256.154	1.9	0.2	0.4
Food at home	245.094	244.108	245.420	0.6	0.1	0.5
Food away from home	269.251	269.801	270.154	3.6	0.3	0.1
Alcoholic beverages	254.567	255.170	255.996	2.1	0.6	0.3
Housing	280.172	279.617	280.790	3.9	0.2	0.4
Shelter	321.741	321.991	323.233	4.5	0.5	0.4
Rent of primary residence(1)	338.364	339.973	342.109	4.8	1.1	0.6
Owners' equiv. rent of residences(1)(2)	337.539	339.010	340.216	4.6	0.8	0.4
Owners' equiv. rent of primary residence(1)(2)	337.547	339.013	340.221	4.6	0.8	0.4
Fuels and utilities	297.769	289.512	290.634	1.9	-2.4	0.4
Household energy	257.284	246.737	248.092	1.0	-3.6	0.5
Energy services(1)	259.651	248.236	249.739	0.9	-3.8	0.6
Electricity(1)	288.877	277.928	278.983	1.9	-3.4	0.4
Utility (piped) gas service(1)	206.353	193.095	195.765	-2.3	-5.1	1.4
Household furnishings and operations	127.713	127.873	128.853	0.4	0.9	0.8
Apparel	122.676	118.553	114.047	-1.3	-7.0	-3.8
Transportation	205.592	207.818	207.212	5.6	0.8	-0.3
Private transportation	200.274	202.613	202.433	6.2	1.1	-0.1
New and used motor vehicles(3)	99.057	98.876	99.407	0.3	0.4	0.5
New vehicles	145.898	146.188	146.734	-1.0	0.6	0.4
New cars and trucks(3)(4)	101.330	101.528	101.910	-1.0	0.6	0.4
New cars(4)	142.454	142.820	143.318	-1.5	0.6	0.3
Used cars and trucks	131.139	130.151	131.270	-0.4	0.1	0.9
Motor fuel	229.619	236.882	231.080	15.5	0.6	-2.4
Gasoline (all types)	228.558	235.686	229.776	15.4	0.5	-2.5
Gasoline, unleaded regular(4)	225.865	232.907	226.921	15.6	0.5	-2.6
Gasoline, unleaded midgrade(4)(5)	218.107	225.115	220.467	14.9	1.1	-2.1
Gasoline, unleaded premium(4)	225.170	231.940	226.645	14.4	0.7	-2.3
Medical Care	483.541	484.696	484.898	2.1	0.3	0.0
Medical care commodities	373.801	376.052	375.618	4.4	0.5	-0.1
Medical care services	518.068	518.795	519.234	1.5	0.2	0.1
Professional services	353.532	353.472	354.172	0.3	0.2	0.2
Recreation(3)	113.238	113.144	113.486	1.7	0.2	0.3
Education and communication(3)	136.464	136.503	136.336	-0.6	-0.1	-0.1
Other goods and services	428.217	428.094	425.924	3.6	-0.5	-0.5
Commodity and Service Group
All Items	257.223	257.126	257.347	3.1	0.0	0.1
Commodities	181.256	181.303	180.621	2.2	-0.4	-0.4
Commodities less food & beverages	144.238	144.413	143.138	2.4	-0.8	-0.9
Nondurables less food & beverages	187.122	187.376	184.168	4.8	-1.6	-1.7
Nondurables less food, beverages, and apparel	232.626	235.672	233.215	6.9	0.3	-1.0
Durables	105.371	105.477	105.804	-0.9	0.4	0.3
Services	327.590	327.355	328.447	3.7	0.3	0.3
Rent of shelter(2)	342.547	342.816	344.127	4.5	0.5	0.4
Transportation services	304.522	307.585	308.597	6.3	1.3	0.3
Other services	345.744	345.295	346.360	1.4	0.2	0.3
Special aggregate indexes:
All items less medical care	246.875	246.723	246.945	3.2	0.0	0.1
All items less food	257.648	257.590	257.704	3.3	0.0	0.0
All items less shelter	232.026	231.779	231.566	2.3	-0.2	-0.1
Commodities less food	148.337	148.525	147.296	2.4	-0.7	-0.8
Nondurables	221.568	221.572	220.251	3.2	-0.6	-0.6
Nondurables less food	192.146	192.421	189.420	4.6	-1.4	-1.6
Nondurables less food and apparel	234.429	237.254	235.092	6.4	0.3	-0.9
Services less rent of shelter(2)	345.234	344.306	345.232	2.5	0.0	0.3
Services less medical care services	314.279	313.983	315.113	3.9	0.3	0.4
Energy	244.605	244.002	241.328	8.4	-1.3	-1.1
All items less energy	260.273	260.214	260.653	2.8	0.1	0.2
All items less food and energy	261.863	261.853	262.213	2.9	0.1	0.1
Commodities less food and energy commodities	139.704	139.013	138.320	0.1	-1.0	-0.5
Energy commodities	233.954	241.600	235.730	15.3	0.8	-2.4
Services less energy services	332.752	333.212	334.281	3.8	0.5	0.3
Footnotes (1) This index series was calculated using a Laspeyres estimator. All other item stratum index series were calculated using a geometric means estimator. (2) Index is on a December 1982=100 base. (3) Indexes on a December 1997=100 base. (4) Special index based on a substantially smaller sample. (5) Indexes on a December 1993=100 base.
Regions defined as the four Census regions. West includes Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming. NOTE: Index applies to a month as a whole, not to any specific date. Data not seasonally adjusted.