💸 インフレと購買力
ビッグマックは1968年に約$0.49でした。今では約$5.79です。なぜお金は価値を失い、どうやって守ればよいのでしょうか?
実例と経済理論を通して探ります。
💡 インフレとは何ですか?
物価が持続的に上昇し、お金の購買力が低下する経済現象です。映画のチケットが1990年に約$2.89で今は約$10.78だとすると、同じお金で買えるものは少なくなっています。年3%のインフレが24年続くと、物価はおよそ2倍になります(複利ベース)。
中央銀行が多く発行するほど、お金は相対的に希少でなくなり、その価値は下がります。
景気が過熱したり消費が急増したりすると、供給が需要に追いつかず物価が上がります。
石油・原材料・賃金が上がると、企業はその負担を消費者物価に転嫁します。
💰 なぜ投資が必要なのですか?
預金金利が2%でインフレが3%なら、お金を銀行に置いておくことは実質的に毎年1%の損失です。資産を本当に増やすには、インフレを上回るリターンが必要です。米国CPI(BLS)によれば、物価は1990年から2026年にかけて約2.4倍になりました。
Gasoline increase
11x
1960: $0.31/gal → 2024: $3.30
Movie ticket increase
17x
1960: $0.69 → 2024: $11.51
Median new home increase
23x
1963: $18,000 → 2024: $420,300
US dollar purchasing power
-96.5%
1913 $1 = 2024 $0.035
データ出所
Each item's price is from U.S. official series — BLS CPI (Average Price series), EIA, USPS, U.S. Census Bureau & HUD, U.S. Dept. of Labor, and NCES/College Board. Per-item sources are shown at the bottom of each card. Some early-year values (before the modern series begins) are estimates, flagged in each note.
物価変動指数(1980 = 100)
単位が異なっても同じ基準で比較できます。ラインが急なほど、速く上昇したことを意味します。
Big Mac (McDonald's)
1 sandwich
12倍
1968→2025
Source: The Economist Big Mac Index (via Statista) + McDonald's menu-price history (History.com). Early-year figures are approximate; prices vary by US location.
Gasoline (regular)
1 gallon
11倍
1960→2024
Source: U.S. Energy Information Administration (EIA) annual average retail price, regular grade; cross-checked vs BLS CPI gasoline series. Includes taxes.
Whole milk
1 gallon
4倍
1960→2024
Source: BLS Average Price series (Milk, Fresh, Whole, per gallon; FRED APU0000709112) via U.S. Inflation Calculator. Pre-1995 values reconstructed from the BLS half-gallon series (estimate).
Eggs (Grade A, large)
1 dozen
6倍
1960→2024
Source: BLS Average Price series (Eggs, Grade A, Large, per dozen; FRED APU0000708111) via U.S. Inflation Calculator. 1960 value is an estimate (predates modern series).
White bread
1 loaf (~1 lb)
10倍
1960→2024
Source: BLS Average Price series (Bread, White, Pan, per lb; FRED APU0000702111; starts 1980) via TradingEconomics, Stacker. 1960 value is an estimate.
Ground coffee
1 lb (ground roast)
2倍
1980→2024
Source: BLS Average Price series (Coffee, 100%, Ground Roast, per lb; FRED APU0000717311; starts 1980) via U.S. Inflation Calculator. Per pound of ground coffee, not a cafe cup.
Movie ticket
1 admission
17倍
1960→2024
Source: NATO (National Association of Theatre Owners / Cinema United) annual average admission, cross-referenced with Box Office Mojo. 2020 uses the 2019 value (COVID makes 2020 unreliable).
First-class stamp (1 oz)
1 stamp
17倍
1960→2024
Source: USPS first-class rate (first ounce) in effect each year, cross-checked vs Wikipedia 'History of United States postage rates'.
Median new home price
median new home sold
23倍
1963→2024
Source: U.S. Census Bureau & HUD, median sales price of new homes sold (series MSPNHSUSA). Series starts 1963; 1963 value used as the earliest point.
Average new car price
avg new vehicle
19倍
1960→2024
Source: J.D. Power/NADA historical averages (1960–2000) and Kelley Blue Book / Cox Automotive average transaction price (2010+). Measure shifts ~2010, so pre-2010 values are approximate.
Federal minimum wage
per hour
7倍
1960→2024
Source: U.S. Department of Labor 'History of Federal Minimum Wage Rates', cross-checked vs FRED. Rate in effect during each year; unchanged at $7.25 since July 2009.
Public 4-yr tuition (in-state)
in-state, 1 year
26倍
1970→2024
Source: NCES Digest of Education Statistics + College Board 'Trends in College Pricing'. Published in-state tuition and required fees (excludes room & board), academic year beginning that year.
Coca-Cola (single serving)
1 bottle/can
20倍
1960→2024
Source: decade-by-decade retail-price journalism (24/7 Wall St., GeekSpin). No official series and container size varies by era, so all values are indicative estimates.
📋 結果は過去のデータに基づくものです。過去のリターンは将来のリターンを保証しません。
📋 本サービスは投資アドバイスではなく、投資を理解するための教育目的で提供されています。