チェック5: インフレ調整で時価を実質値に揃える

import os
import cpi
import matplotlib.pyplot as plt
import pandas as pd
import seaborn as sns

from full_fred.fred import Fred

cpi.update()  # CPI データを最新に更新
fred = Fred()  # 環境変数 FRED_API_KEY が設定されている前提

def get_fred_data(series_id, start="2013-01-01", end=None):
    df = fred.get_series_df(series_id)[["date", "value"]].copy()
    df["date"] = pd.to_datetime(df["date"])
    df["value"] = pd.to_numeric(df["value"], errors="coerce")
    df = df.set_index("date")
    if end:
        df = df.loc[start:end]
    else:
        df = df.loc[start:]
    return df

data = get_fred_data("MEHOINUSA646N", start="2013-01-01")
data.head()

plt.figure(figsize=(12, 6))
sns.lineplot(data=data, x="date", y="value")
plt.title("Median Household Income (nominal)")
plt.show()

data["real_value"] = [
    cpi.inflate(row.value, idx.year) for idx, row in data.iterrows()
]

plt.figure(figsize=(12, 6))
sns.lineplot(data=data, x="date", y="value", label="Nominal (MEHOINUSA646N)")
sns.lineplot(data=data, x="date", y="real_value", label="Adjusted by CPI")
plt.legend()
plt.show()

data_real = get_fred_data("MEHOINUSA672N", start="2013-01-01")

plt.figure(figsize=(12, 6))
sns.lineplot(data=data_real, x="date", y="value", label="MEHOINUSA672N (real)")
sns.lineplot(data=data, x="date", y="real_value", label="MEHOINUSA646N adjusted")
plt.legend()
plt.show()