If tax-loss harvesting pays a dividend that grows with volatility, how much more risk should a taxable mean-variance investor hold?
Read the paper on SSRN ↗ CiteKey results
- At the base calibration the optimal equity weight moves from 0.65 to 0.92, about 41%, and the after-tax reward-to-risk slope from 0.31 to 0.43.
- The dividend is convex on the downside, so a power-utility investor tilts by 48 to 49% instead of 42%.
- Fitted to index data from 1993 to 2026, the dividend is 91 basis points in calm markets and 319 in turbulent ones.
- In one simulated account the dividend falls from 160 basis points in year one to 21 by year five.
Summary
A cash flow that grows with volatility
When a stock in a taxable account falls below its cost basis, its owner can sell it, buy a close substitute and bank a capital loss without leaving the market. That loss shelters gains realized elsewhere, and the tax it saves is cash. How much an account collects this way depends on how far and how often its holdings fall, so the benefit rises with volatility, which is an odd property for anything a mean-variance investor receives. Volatility is what that investor pays to avoid.
Papers on portfolio choice price variance as a cost, and papers on harvesting price volatility as a source of extra return. We wanted both in one objective. So the paper treats the yearly harvest benefit as a dividend: roughly proportional to volatility, and larger in the years the portfolio does badly. We add it to a one-period mean-variance problem and solve for the best share in the risky asset again.
The base case
The dividend changes the solution in two ways. Its expected level adds return, and because the dividend pays more when markets fall, it also offsets part of the variance the investor carries. Both push the optimal weight up.
We calibrated the dividend with a fixed-seed simulation of a 60-name sleeve that harvests whenever a name trades 5% below its basis. Take portfolio volatility of 16%, an equity premium of 5%, a blended tax rate of 0.30 and a usage factor of 0.35, meaning roughly a third of the idealized paper losses become usable tax savings. Those inputs give a dividend of 1.6% a year. For a moderately risk-averse investor the optimal equity weight moves from 0.65 to 0.92, about 41% higher, and the after-tax reward-to-risk slope goes from 0.31 to 0.43.
The percentage increase does not depend on risk aversion. Table 1 shows 41.5% at every level, while the move measured in weight shrinks from 0.41 for an aggressive investor to 0.14 for a conservative one. We had expected the hedging channel to count for more. It adds about 7%; the level of the dividend supplies the rest.
There is also an asymmetry between the two sides of the problem. Losses are harvested name by name, so the dividend follows the volatility of individual stocks, while the variance penalty falls on the diversified portfolio. In the calibration that raises the scaling against portfolio volatility by a factor of 1.79.
Where the straight line holds
Figure 1 plots the simulated harvest yield against name volatility. Between about 0.16 and 0.40 the curve is nearly straight. Below that band few names fall 5% and harvesting is starved; above it the curve bends over as capacity binds. The usage factor is the softest input we have, and moving it from 0.20 to 1.0 takes the weight increase from 23% to 134%.
Removing the simplifications
Version 2 of the paper drops, one at a time, the linear dividend, the single period and the assumption that the inputs are known. Start with shape. On 3,000 fresh one-year paths the dividend is convex on the downside: in the worst tenth of years, when the sleeve loses 19%, it averages 284 basis points where the straight line predicts 252, and in no year does it go below zero, although the line says it can. A power-utility investor likes that floor. She tilts by 48 to 49% instead of 42%.
Noise? An uncertain usage factor? Neither moves the optimum by as much as a tenth of a percent, because both enter the variance penalty in units of the dividend squared, and the dividend is small next to volatility. A cap at a weight of one binds for investors whose risk aversion is below 2.76. It cuts the tilt short and never reverses it. At the base case the tilt is worth 26 basis points a year in certainty-equivalent terms.
The dividend changes with the market and with age
Does the dividend stay put? No. We fitted a two-regime hidden Markov model to daily returns on the S&P 500 trust from February 1993 to August 2026, 8,445 observations in all, and pushed each regime's volatility through the simulated yield curve: 91 basis points of dividend in calm spells, 319 in turbulent ones. Calendar years spread wider still, from 41 basis points in 2017 to 440 in 2008. In the six years the index fell the figure averaged 282, against 151 in the years it rose, and its correlation with the year's return is -0.54.
Account age matters as much. Over five simulated years one account's dividend runs 160 basis points, then 55, and reaches 21 by year five, about an eighth of where it began, since every recovery embeds a gain and fewer names end up below cost. What forecasts next year's harvest best is the account's own basis position, which custodians already report; market variables add little. Out of sample, R² goes from 0.16 using the year alone to 0.35 once last year's yield and the two basis measures are in. In the model, then, the tilt is largest in an account's first year and fades after it.
A recurrent network, finally, read each simulated year's harvest off its daily path with an R² of 0.99, against 0.58 for a rule on realized volatility. That helps in measuring a dividend after the fact. By then, of course, the loss is already on the tax return.
Limits
The yield curve comes from simulated prices with a fixed correlation, and the yearly figures push real index volatility through that curve, so they know nothing about the actual stocks in a given year. Repurchasing at the same price, as the simulation does, is forbidden by the 30-day wash-sale rule; the usage factor stands in for that gap. This paper is educational; it describes a model and no real account.
Who this is for: Researchers in after-tax portfolio choice, CPAs who work with harvested losses, and journalists covering direct indexing.
Figures
Tables
| γ | w0* | wD* (mean only) | wD* (full) | wD* (brute force) | Δ w | % increase |
|---|---|---|---|---|---|---|
| 2 | 0.977 | 1.293 | 1.382 | 1.390 | 0.405 | 41.5 |
| 3 | 0.651 | 0.862 | 0.921 | 0.925 | 0.270 | 41.5 |
| 4 | 0.488 | 0.647 | 0.691 | 0.695 | 0.203 | 41.5 |
| 6 | 0.326 | 0.431 | 0.461 | 0.465 | 0.135 | 41.5 |
| τ | dividend D | w0* | wD* | Δ w |
|---|---|---|---|---|
| 0.000 | 0.0000 | 0.651 | 0.651 | 0.000 |
| 0.150 | 0.0081 | 0.651 | 0.782 | 0.131 |
| 0.238 | 0.0129 | 0.651 | 0.863 | 0.212 |
| 0.300 | 0.0162 | 0.651 | 0.921 | 0.270 |
| 0.408 | 0.0221 | 0.651 | 1.027 | 0.376 |
| φ | dividend D | wD* | % increase |
|---|---|---|---|
| 0.20 | 0.0093 | 0.801 | 23.1 |
| 0.35 | 0.0162 | 0.921 | 41.5 |
| 0.50 | 0.0232 | 1.048 | 61.0 |
| 0.70 | 0.0324 | 1.228 | 88.7 |
| 1.00 | 0.0463 | 1.525 | 134.3 |
| γ | w0* | closed form, Section 3 | closed form at the paths' D, β | mean-variance on paths | CRRA, no dividend | CRRA, with dividend | CRRA % increase |
|---|---|---|---|---|---|---|---|
| 2 | 0.977 | 1.382 | 1.390 | 1.390 | 1.110 | 1.640 | 47.7 |
| 3 | 0.651 | 0.921 | 0.927 | 0.925 | 0.740 | 1.105 | 49.3 |
| 4 | 0.488 | 0.691 | 0.695 | 0.695 | 0.555 | 0.825 | 48.6 |
| 6 | 0.326 | 0.461 | 0.463 | 0.465 | 0.370 | 0.550 | 48.6 |
| variant | w* | % increase |
|---|---|---|
| closed form, Section 3 | 0.921 | 41.5 |
| plus the dividend's residual noise (sε = 0.0037) | 0.921 | 41.4 |
| plus an uncertain φ, uniform on [0.20, 0.50] (sD = 0.0040) | 0.921 | 41.4 |
| both | 0.920 | 41.3 |
| worst case, φ = 0.20 | 0.801 | 23.1 |
| CRRA on the simulated paths | 1.105 | 49.3 |
| capped at w ≤ 1 (cap slack at γ=3) | 0.921 | 41.5 |
| γ | w0* | wD* | capped | cap binds | value of tilt, uncapped | value that survives the cap | cost of the cap |
|---|---|---|---|---|---|---|---|
| 1.5 | 1.302 | 1.843 | 1.000 | yes | 52.5 | 0.0 | 127.6 |
| 2.0 | 0.977 | 1.382 | 1.000 | yes | 39.4 | 4.4 | 34.9 |
| 2.5 | 0.781 | 1.106 | 1.000 | yes | 31.5 | 28.2 | 3.3 |
| 3.0 | 0.651 | 0.921 | 0.921 | no | 26.2 | 26.2 | 0.0 |
| 4.0 | 0.488 | 0.691 | 0.691 | no | 19.7 | 19.7 | 0.0 |
| 6.0 | 0.326 | 0.461 | 0.461 | no | 13.1 | 13.1 | 0.0 |
| regime | index vol | name vol | Y | D (bp) | β | w0* | wD* | % increase | time share | mean stay (days) |
|---|---|---|---|---|---|---|---|---|---|---|
| calm | 0.108 | 0.19 | 0.087 | 91 | 0.034 | 1.439 | 1.821 | 26.6 | 0.69 | 71 |
| turbulent | 0.292 | 0.52 | 0.304 | 319 | 0.028 | 0.196 | 0.339 | 73.3 | 0.31 | 32 |
| mixture, regime unknown | 0.486 | 0.680 | 39.8 |
| year | index vol | index return (%) | name vol | D (bp) | w0* | wD* | capped |
|---|---|---|---|---|---|---|---|
| 1994 | 0.105 | +0.4 | 0.19 | 89 | 1.50 | 1.89 | 1.00 |
| 1995 | 0.085 | +38.0 | 0.15 | 65 | 2.29 | 2.77 | 1.00 |
| 1996 | 0.131 | +22.5 | 0.23 | 121 | 0.98 | 1.30 | 1.00 |
| 1997 | 0.201 | +33.5 | 0.36 | 217 | 0.41 | 0.63 | 0.63 |
| 1998 | 0.223 | +28.7 | 0.40 | 251 | 0.34 | 0.54 | 0.54 |
| 1999 | 0.181 | +20.4 | 0.32 | 184 | 0.51 | 0.74 | 0.74 |
| 2000 | 0.239 | -9.7 | 0.43 | 267 | 0.29 | 0.48 | 0.48 |
| 2001 | 0.221 | -11.8 | 0.40 | 249 | 0.34 | 0.54 | 0.54 |
| 2002 | 0.264 | -21.6 | 0.47 | 291 | 0.24 | 0.40 | 0.40 |
| 2003 | 0.165 | +28.2 | 0.30 | 167 | 0.61 | 0.87 | 0.87 |
| 2004 | 0.112 | +10.7 | 0.20 | 95 | 1.34 | 1.71 | 1.00 |
| 2005 | 0.103 | +4.8 | 0.18 | 86 | 1.56 | 1.96 | 1.00 |
| 2006 | 0.100 | +15.8 | 0.18 | 83 | 1.66 | 2.08 | 1.00 |
| 2007 | 0.159 | +5.1 | 0.29 | 162 | 0.66 | 0.93 | 0.93 |
| 2008 | 0.412 | -36.8 | 0.74 | 440 | 0.10 | 0.19 | 0.19 |
| 2009 | 0.266 | +26.4 | 0.48 | 293 | 0.24 | 0.40 | 0.40 |
| 2010 | 0.179 | +15.1 | 0.32 | 181 | 0.52 | 0.75 | 0.75 |
| 2011 | 0.231 | +1.9 | 0.41 | 259 | 0.31 | 0.51 | 0.51 |
| 2012 | 0.127 | +16.0 | 0.23 | 117 | 1.03 | 1.36 | 1.00 |
| 2013 | 0.111 | +32.3 | 0.20 | 94 | 1.36 | 1.73 | 1.00 |
| 2014 | 0.113 | +13.5 | 0.20 | 97 | 1.32 | 1.68 | 1.00 |
| 2015 | 0.155 | +1.2 | 0.28 | 156 | 0.70 | 0.98 | 0.98 |
| 2016 | 0.131 | +12.0 | 0.23 | 122 | 0.97 | 1.30 | 1.00 |
| 2017 | 0.067 | +21.7 | 0.12 | 41 | 3.66 | 4.21 | 1.00 |
| 2018 | 0.171 | -4.6 | 0.31 | 173 | 0.57 | 0.82 | 0.82 |
| 2019 | 0.125 | +31.2 | 0.22 | 114 | 1.06 | 1.40 | 1.00 |
| 2020 | 0.336 | +18.3 | 0.60 | 369 | 0.15 | 0.27 | 0.27 |
| 2021 | 0.130 | +28.7 | 0.23 | 121 | 0.99 | 1.31 | 1.00 |
| 2022 | 0.243 | -18.2 | 0.43 | 270 | 0.28 | 0.46 | 0.46 |
| 2023 | 0.131 | +26.2 | 0.23 | 122 | 0.98 | 1.30 | 1.00 |
| 2024 | 0.126 | +24.9 | 0.23 | 115 | 1.05 | 1.39 | 1.00 |
| 2025 | 0.193 | +17.7 | 0.35 | 204 | 0.45 | 0.67 | 0.67 |
| year | Y | D (bp), 8% drift | β | wD* | % increase | value of tilt (bp) | names below basis | price / basis | D (bp), 0% drift |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 0.152 | 160 | 0.032 | 0.917 | 40.9 | 25.4 | 6.9% | 1.27 | 192 |
| 2 | 0.052 | 55 | 0.017 | 0.747 | 14.8 | 3.4 | 4.4% | 1.45 | 80 |
| 3 | 0.033 | 35 | 0.010 | 0.711 | 9.2 | 1.3 | 3.5% | 1.64 | 56 |
| 4 | 0.025 | 26 | 0.008 | 0.697 | 7.0 | 0.8 | 2.8% | 1.81 | 47 |
| 5 | 0.021 | 21 | 0.007 | 0.688 | 5.7 | 0.5 | 2.5% | 2.00 | 40 |
| reader | inputs | RMSE | R² | RMSE, no volatility shift | RMSE, with shift | implied error in w* at γ=3 |
|---|---|---|---|---|---|---|
| affine in realized volatility | 1 number | 0.074 | 0.58 | 0.073 | 0.075 | 0.108 |
| ridge on path features | 7 numbers | 0.037 | 0.90 | 0.035 | 0.039 | 0.054 |
| ridge plus timing features | 10 numbers | 0.037 | 0.90 | 0.035 | 0.039 | 0.053 |
| LSTM on the daily sequence | 252 × 3 | 0.009 | 0.99 | 0.008 | 0.011 | 0.014 |
| LSTM, squared channels appended | 252 × 6 | 0.010 | 0.99 | 0.008 | 0.012 | 0.015 |
| A: professional | B: retiree | C: early-career | |
|---|---|---|---|
| taxable wealth | $2,000,000 | $800,000 | $250,000 |
| rate on harvested losses τ | 0.408 | 0.238 | 0.300 |
| usage factor φ | 0.50 | 0.35 | 0.20 |
| risk aversion γ | 3 | 4 | 2 |
| dividend D (bp / yr) | 315 | 129 | 93 |
| loading β | 0.063 | 0.026 | 0.019 |
| w0* | 0.651 | 0.488 | 0.977 |
| wD*, uncapped | 1.210 | 0.647 | 1.202 |
| wD*, capped | 1.000 | 0.647 | 1.000 |
| % increase, uncapped | 85.8 | 32.5 | 23.1 |
| equity dollars, tax-indifferent | $1,302,083 | $390,625 | $244,141 |
| equity dollars, tax-aware | $2,000,000 | $517,551 | $250,000 |
| extra equity dollars | $697,917 | $126,926 | $5,859 |
| dividend, dollars per year | $63,018 | $6,659 | $2,317 |
| value of the tilt (bp / yr) | 90.3 | 12.2 | 2.5 |
| value of the tilt, dollars per year | $18,063 | $978 | $62 |
Abstract
Systematic tax-loss harvesting produces a benefit that grows with volatility, which is what a mean-variance investor pays to avoid. This paper writes the harvest benefit into the objective as a volatility-linked, stochastic cash flow that pays more when the portfolio does worse. We model the annual harvest benefit as a yield approximately proportional to volatility, add it to a single-period mean-variance problem, and re-derive the optimal risky weight and the after-tax capital allocation line: w* = (pi + D) / (gamma * sigma^2 * (1-beta)^2), with D the dividend level and beta its countercyclical loading. For a diversified equity sleeve calibrated to a fixed-seed harvesting simulation (base dividend 1.6% per year, tax rate 0.30, usage factor 0.35), the optimal allocation to the volatile asset rises about 41% relative to the tax-indifferent case and the after-tax reward-to-risk slope steepens about 37%. What is new is the frontier geometry: the slope of the after-tax frontier changes, not a single point, and the dividend rides name-level volatility while the variance penalty falls on the diversified portfolio.
Version 2 removes the linearization, the single period and the fixed parameters. On the full simulated paths the dividend is convex on the downside and a power-utility investor tilts by 48 to 49% rather than 42%; the dividend's noise and an uncertain usage factor barely move the optimum; a cap on the finished allocation truncates the tilt below a risk aversion of 2.8. A two-regime model fitted to 33 years of index data puts the dividend at 91 basis points in calm markets and 319 in turbulent ones, and year by year from 41 basis points in 2017 to 440 in 2008. The dividend decays to an eighth of its first-year level by year five of an account's life, and the account's embedded gain, not realized volatility, predicts next year's yield. A recurrent network reads the year's harvest off the daily path almost exactly; we say what that buys and what it does not.
Keywords: tax-loss harvesting, after-tax portfolio choice, efficient frontier, mean-variance optimization, direct indexing, stochastic dividend, volatility, tax-aware investing, certainty equivalent, risk-taking, regime switching, sequence models
How to cite
Majumdar, A. (2026). Harvesting as a Stochastic Dividend: The After-Tax Efficient Frontier Revisited. SSRN Working Paper No. 7507839. https://ssrn.com/abstract=7507839
@techreport{majumdar_harvesting_stochastic_dividend,
author={Majumdar, Anirban},
title={Harvesting as a Stochastic Dividend: The After-Tax Efficient Frontier Revisited},
institution={SSRN},
number={7507839},
year={2026},
url={https://ssrn.com/abstract=7507839}}