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1990issue C051-11

Constructing a nominal index price from earnings and a fitted yield

A constructed nominal price is four-quarter earnings divided by a fitted effective yield. The identity is derived on a quarterly earnings cycle, evaluated monthly, and judged by comparing implied earnings with later realized earnings.

  • Nominal price is a constructed baseline: four-quarter earnings divided by a fitted effective yield, not the observed market print.
  • The effective yield is the three-month bill rate raised to a linear combination fitted by linear least squares on a constant, the bill-minus-inflation spread, and the bill-minus-bond spread.
  • The identity is derived on a quarterly earnings cycle and then evaluated monthly so the constructed path can be compared with the contemporaneous index.
  • The construction is judged by comparing implied four-quarter-ahead earnings with later realized earnings, not by a trading rule.
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A baseline price, not a market print

A constructed nominal price is defined as four-quarter earnings divided by a fitted effective yield. That nominal price is a baseline index level implied by those two inputs, not the observed market print.

The identity is derived on a quarterly earnings cycle and then evaluated monthly. The finer sampling interval lets the constructed path be compared with the contemporaneous index.

Fitting the effective yield

The effective yield is a regression-assembled interest factor used as the divisor in the nominal-price identity. It is formed from the three-month bill rate raised to a linear combination of a constant, the bill-minus-inflation spread, and the bill-minus-bond spread.

Linear least squares supplied the three coefficients: 0.91022 on the constant, 0.03083 on the bill-minus-inflation spread, and 0.04983 on the bill-minus-bond spread.

A yield exponent in the early sample

Before 1968 the fitted yield diverges from conventional bill and bond rates, so the construction applies a yield exponent. After that early sample the extra power later fluctuates around 1.

Implied earnings as the construction check

Solving the same identity for earnings produces implied earnings: a four-quarter-ahead total that can be compared with later realized earnings. One late-1980s episode showed an implied figure of 34 against later realized earnings of 23.75.

Editorial: that rearrangement is the out-of-sample test of the construction, not a signal for entering or exiting a market.

An exponential earnings trend

Average four-quarter-ahead earnings are represented by a least-squares exponential trend of 1.61485 times 1.06974 raised to a time index. The time index is a calendar coordinate equal to year plus quarter divided by four, minus 51.

Levels, changes, and a consistency check

In the examined history, the level of price shows little correlation with the level of earnings, while yearly price change aligns more closely with the yearly change in earnings four quarters after the price observation.

Yearly earnings growth rates of a large-capitalization industrial average and a broad market index are compared as a consistency check on whether one series was treated as representative of the other.

Educational research material, not investment advice. Historical source context does not establish present-day performance.
3 of 43 in the Linear regression track
19901-6 pp.Next on Linear regressionEndpoint-pinned price paths are not forecastsEndpoint pinning forces the first and last outputs to equal the first and last observations, so the path has no demonstrated validity beyond the last supplied print.
All readings on this track · 43 readings
  1. 1990Constructing dollar baselines from rates, inflation, and residuals
  2. 1990Constructing a nominal index value from forward earnings and fitted yield
  3. 1990Constructing a nominal index price from earnings and a fitted yield
  4. 1990Endpoint-pinned price paths are not forecasts
  5. 1990Constructing least-squares polynomial smoothers
  6. 1991Endpoint growth rates versus linear-regression consistency
  7. 1991Out-of-sample checks for linear growth fits
  8. 1991Trend as persistence, not a straight line
  9. 1991Quadratic trend, residual oscillator, and a secondary cycle calendar
  10. 1991Time-origin offset and residual-price divergence on a quadratic least-squares fit
  11. 1991A least-squares trendline from ordered prices
  12. 1992Constructing log-linear growth and reliability screens
  13. 1992Constructing log-linear growth-rate baselines
  14. 1992Next-session high, low, and close from rolling linear regression
  15. 1993Auditing an index price-earnings multiple with short-rate regression
  16. 1994Regression-seeded nested exponential price filter
  17. 1994Constructing the double exponential average from lag cancellation
  18. 1994Evaluating money supply as a linear leading-index baseline
  19. 1995Constructing least-squares trend channels
  20. 1995Linear baseline holdout checks for annual bill-rate forecasts
  21. 1995Projection bands from high and low regression slopes
  22. 1995Evaluating a least-squares end-point moving average on a known test series
  23. 1996Constructing an endpoint moving average from a least-squares line
  24. 1996Scoring equity path consistency with a k-ratio overlay
  25. 1996Evaluating month-end yield gaps for equity regimes
  26. 1996Constructing session-indexed standard error bands
  27. 1998Evaluating linear regression baselines for index valuation
  28. 1998R-squared as a two-state trend filter from a price-time fit
  29. 2000Second-order moving-average lag correction
  30. 2002Price regression line versus beta for index tracking
  31. 2003Regression slope with an r-squared trend confidence gate
  32. 2003Constructing finite-volume-element divergence with slope comparison
  33. 2004Building a daily score from regression, retracement, and volume
  34. 2004Constructing least-squares trendlines from ordered prices
  35. 2007Rectangle breakout targets beyond height
  36. 2007Confirming a price trend with regression slope and r-squared
  37. 2008A linear-regression angle assembled as one trend filter
  38. 2010A two-state swing machine from four running extremes
  39. 2016Score oil-complex tightness before divergence or regression
  40. 2017Nikkei-yen intermarket divergence as a regime case study
  41. 2017Constructing Calmar ratio and linear regression baselines
  42. 2019Pair-trade layer construction versus average-spread management
  43. 2020A convolution slope built from nested linear regression
All 112 readings tagged Linear regression
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