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Studying asset pricing, I often hear the terms cashflow risk and discount risk but I'm not sure what they mean? The Campbell/Shiller (1988) decomposition includes cashflows (future dividends) and discount rates (expected returns) and hence identifies both risks?

Apparently, the long run risk model from Bansal and Yaron (2004) and the duration model from Lettau and Wachter (2007) discuss cashflow risk whereas the external habit model from Campbell and Cochrane (1999) is about discount risk? The investment decision model from Berk Green and Naik (1999) apparently includes both? What about the simple CAPM and CCAPM?

Campbell and Vuolteenaho (2004) use an ICAPM set-up to decompose market beta in cashflow and discount component and show that value stocks have higher CF betas.

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    $\begingroup$ Historically the earliest Finance models (DDM, CAPM) attributed the price fluctuations of stocks entirely to changing estimates of future business results (earnings, dividends, cash flows), which were assumed to be discounted at an "appropriate discount rate" implictly considered to be fixed. Mainly because of Shiller's research, after 1980 people began to realize that this does not explain what is going on and that the discount rate itself fluctuates over time (for reasons that require investigation). So a "two risks" approach developed trying to separate these two. $\endgroup$ – noob2 Jul 20 at 13:25
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    $\begingroup$ Cash flow risks relate to the company (will they do well or not). Discount risks relate to the investors, if people cannot/do not wish to invest in stocks (for rational or behavioral reasons) the discount rate will be elevated. and both of these factor can change over time. It is difficult to explain the low prices of stocks in 1933 (or other big bear markets) without both of these effects being present simultaneously, Shiller showed. Earnings were temporarily depressed, but investors were scared as well. $\endgroup$ – noob2 Jul 20 at 13:52
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    $\begingroup$ In the present state of theory Cashflow risk and Discount risk are the only two things known to affect stock valuation, yes. That is where we are now. $\endgroup$ – noob2 Jul 20 at 13:56
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    $\begingroup$ The cashflow - discount rate news dichotomy is essentially an accounting identity. Like if prices increase with no change in (the distribution of) cashflows that mechanically means lower returns. $\endgroup$ – fesman Jul 21 at 17:53
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    $\begingroup$ Discount rate news/variation is essentially variation in expected returns. So if the model generates return predictability or variation in expected returns, there is a discount news channel. The old fashioned finance model had a constant discount rate and expected returns so no discount rate news. We don't think this is realistic anymore. $\endgroup$ – fesman Jul 21 at 18:35
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The answer to your question could fill an entire asset pricing text book. Your question mixes theory and empirics.

A different way of looking at it is to look at the identity:

$$ 1 = E[M_t R_t]$$

To generate a sufficient risk premium either you need to have the covariance of the SDF with the the return to be sufficiently high.

Campbell and Cochrane basically change $M_t$ to generate a sufficiently volatile SDF.

Bansal and Yaron, use Epstein-Zin utility and change the standard cash-flow component of dividends. Lettau and Wachter similarly.

Empirically I think this blog post explains it super well: https://johnhcochrane.blogspot.com/2015/04/the-sources-of-stock-market-fluctuations.html

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The cash flow news / discount rate news decomposition is given by

$$r_{t+1}-\mathbb{E}_t[r_{t+1}]=(\mathbb{E}_{t+1}-\mathbb{E}_t)\sum_{j=0}^{\infty}\rho^j\Delta d_{t+1+j}-(\mathbb{E}_{t+1}-\mathbb{E}_t)\sum_{j=1}^{\infty}\rho^j\Delta r_{t+1+j},$$

where $r_{t}$ is log-return $d_{t}$ is log-dividend and $\rho$ is a constant. This follows directly from the Campbell-Shiller decomposition.

Here the second term is discount rate news that determines shocks to the path of expected log-returns. This will be zero if expected stock returns are constant as in older finance theories. On the other hand, it is generally non-zero if returns are predictable. To see this assume we find $\beta\neq 0$ for some predictor $x_t$ so that

$$r_{t+1}=\alpha +\beta x_t+\epsilon_{t+1}.$$

Then the discount rate news component is

$$(\mathbb{E}_{t+1}-\mathbb{E}_t)\sum_{j=1}^{\infty}\beta\rho^j\Delta x_{t+1+j}$$

For simplicity assume the predictor is AR(1) with persistence $\lambda$.

$$(\mathbb{E}_{t+1}-\mathbb{E}_t)\sum_{j=1}^{\infty}\beta\rho^j\Delta x_{t+1+j}=(x_{t+1}-\lambda x_t)\frac{\beta\lambda\rho}{1-\rho\lambda}.$$

Hence return predictability implies that return variation is partly driven by discount rate news. Modern asset pricing theories try to explain why certain variables $x_t$ can forecast returns. In the habit model the key predictor is consumption growth so higher consumption means lower expected returns. This can also explain why price-dividend ratios forecast returns. In the long run risk model there are two predictors: expected consumption growth and consumption volatility.

The cash flow news component does not create return predictability but creates variance in returns as a positive shock to future cash flows leads to higher returns.

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  • $\begingroup$ That is the identity from Campbell and Shiller right? Could you perhaps expand on how different models use different channels to explain various anomalies? $\endgroup$ – Alex Jul 23 at 18:17
  • $\begingroup$ @Alex Yes. I've expanded the answer. $\endgroup$ – fesman Jul 24 at 8:10
  • $\begingroup$ Thank you so much, I wish I could accept and reward both answers! $\endgroup$ – Alex Jul 24 at 9:34

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