WASHINGTON — The United States Postal Service’s price hikes, including an increase in the price of a First-Class Mail single-piece letter from 46 cents to 49 cents, went into effect as of this week. The proposed changes are intended to generate $2 billion in incremental annual revenue for the Postal Service.Highlights of the new single-piece First-Class Mail pricing include:• Letters (1 oz.) — 3-cent increase to 49 cents • Letters additional ounces — 1-cent increase to 21 cents • Letters to all international destinations (1 oz.) — $1.15 • Postcards — 1-cent increase to 34 cents Stamp prices have stayed consistent with the average annual rate of inflation of 4.2 percent since the Postal Service was formed in 1971.Pricing for Standard Mail, Periodicals, Package Services and Extra Services also will be adjusted as part of a filing to the Postal Regulatory Commission scheduled to take place Sept. 26.The Governors of the Postal Service voted Sept. 24 to seek price increases above the typical annual increases associated with changes in the Consumer Price Index.In a letter disseminated to customers today, Board of Governors Chairman Mickey Barnett described the “precarious financial condition” of the Postal Service and the “uncertain path toward enactment of postal reform legislation” as primary reasons for seeking price changes above the CPI increase. He also indicated that the price adjustment above the CPI increase is necessary in order to ensure that the Postal Service will be able to maintain and continue the development of postal services of the type and quality which America needs.“Of the options currently available to the Postal Service to align costs and revenues, increasing postage prices is a last resort that reflects extreme financial challenges,” said Barnett in the letter.