Borrowing and Spending in the Money: Debt Substitution and the Cash-Out Refinance Channel of Monetary Policy
What this paper finds — and why it matters
Overview
Research Question. Does monetary policy stimulate household borrowing and consumption by enabling cash-out mortgage refinancing (“the cash-out refinance channel”), or does it primarily induce substitution across borrowing products without meaningfully changing total new household borrowing?
Motivation. Prior work (Eichenbaum, Rebelo and Wong 2022; Berger et al. 2021) interprets the strong positive correlation between a borrower’s refinance incentive and cash-out refinancing as evidence of a potent, path-dependent monetary policy transmission channel: when rates fall below a borrower’s outstanding mortgage rate (“in-the-money”), the incentive to refinance generates large cash-out activity and consumption. This interpretation presumes that mortgages are effectively the only household borrowing product and that cash-out refinancing reflects a stimulated demand for new borrowing.
Alternative Hypothesis. The authors argue instead that households have inelastic, exogenous liquidity needs (for consumption smoothing, housing repairs, health shocks, etc.) and satisfy those needs using whichever borrowing product is cheapest given the rate environment. When mortgage rates fall below a borrower’s outstanding rate, cash-out refinancing becomes the least-cost vehicle, so borrowers shift from credit cards, HELOCs, personal loans, and second liens (closed-end seconds) toward cash-out refinancing—substituting borrowing products rather than expanding total borrowing.
Data. The authors use the Equifax Credit Risk Insight Servicing McDash (CRISM) dataset, which anonymously matches credit bureau records to mortgage servicing data (McDash). The main sample is a 16.5% draw of fixed-rate, first-lien mortgage loans observed at monthly frequency during 2013, yielding approximately 35 million loan-month observations. For the long time-series analysis, the full 2006–2021 sample is used. Borrowing events are identified across five credit instruments: cash-out refinance, HELOC, closed-end second (CES), credit card, and personal loan, each requiring at least $5,000 in new credit.
Identification Strategy. The paper uses two complementary approaches to address the endogeneity of mortgage rates and borrower refinance incentives.
Taper Tantrum quasi-experiment (main): In late spring 2013, two FOMC communication events triggered an approximately 80 basis-point increase in the 30-year fixed mortgage rate over the course of one month. Critically, because the shock arose from changes in long-term rate expectations (LSAPs), short-term rates—and thus HELOC and consumer credit rates—were largely unchanged. The authors exploit cross-sectional variation in pre-Taper “rate gaps” (outstanding mortgage rate minus estimated current market rate) using a difference-in-differences design (equation 6) to compare how cash-out and alternative borrowing change after the shock for borrowers with different pre-existing refinance incentives.
Monetary policy surprise IV (2006–2021): Following Berger et al. (2021), the authors instrument for the aggregate share of borrowers with rate gaps between 0 and 2 percentage points using the Bu, Rogers and Wu (2021) (BRW) unified measure of Fed monetary policy shocks, which spans both conventional and unconventional policy. This approach tests whether substitution persists when both long and short rates move together.
Main Findings.
Extensive margin (probability of borrowing): After the Taper Tantrum, the monthly probability of cash-out refinancing declines for all rate gap bins, most strongly for borrowers pushed out of the money by the rate increase (a roughly 0.0012 percentage-point monthly probability decline—more than 85 percent below baseline—for borrowers with pre-Taper rate gaps of approximately 1 percent). Simultaneously, the probability of other borrowing (HELOCs, credit cards, personal loans, CES) rises in a near-mirror image, especially for borrowers at intermediate rate gaps. The combined effect on total borrowing probability is negligible and shows little variation with rate gap.
Intensive margin (amount borrowed conditional on borrowing): Conditional on a cash-out refinance occurring after the Taper, the average extraction amount increases, consistent with a borrower-selection effect: low-liquidity-need borrowers, who face the highest effective borrowing cost increase when they move out of the money, disproportionately exit cash-out refinancing, leaving behind a pool of high-liquidity-need borrowers. For borrowers with pre-Taper rate gaps of around 1 percent, the conditional cash-out amount rises about 20 percent after the Taper.
Aggregate borrowing elasticity: Combining extensive and intensive margin estimates via a hurdle model, a 1 percentage-point increase in mortgage rates reduces total new household borrowing by between 0 and 8 percent (the aggregate borrowing elasticity is not statistically significantly different from zero at the preferred estimate, with a lower-bound of −8 percent), compared with a cash-out probability elasticity of approximately −45 percent in absolute terms.
Debt paydown: About 10–12 percent of new mortgage debt from cash-out refinances is used to pay down other outstanding debt, and this share is constant across rate gap groups and is not affected by the Taper, implying the MPC from cash-out borrowing does not vary with the rate environment.
Conventional monetary policy: Using the BRW IV over 2006–2021, the IV first stage yields an F-statistic of approximately 11. The cash-out extensive margin responds positively to the in-the-money share (elasticity 3.5 in IV), while other borrowing responds negatively (elasticity −0.87 in IV), and the all-borrowing elasticity is 0.09 and statistically insignificant. The intensive margin results are directionally consistent: conditional cash-out amounts fall as more borrowers are in the money, while total borrowing amounts respond positively (but insignificantly). Substitution thus holds even when both long and short rates move together.
Implications for Path Dependence. Because out-of-the-money borrowers substitute toward non-cash-out products, the non-linear dependence of cash-out refinancing on the distribution of outstanding mortgage rates does not translate into a correspondingly path-dependent total borrowing response. A back-of-the-envelope calculation using standard MPC assumptions (100 percent for cash-out, 80 percent for rate-term savings) and empirical refinancing frequencies and amounts (average first-lien equity extraction of $40,000 vs. average annual payment savings of $3,000 from rate-term refinancing, with rate-term frequency about 1.5x higher and semi-elasticity about 2x larger) implies that the potential near-term consumption stimulus from cash-out refinancing is approximately 5.5 times larger than from rate-term refinancing—making cash-out the dominant channel in principle. But because debt substitution substantially offsets the interest-rate sensitivity of cash-out refinancing, and because the path dependence of cash-out refinancing is largely eliminated by borrower substitution, the paper concludes that the overall path dependence of monetary policy is weaker than suggested by Berger et al. (2021) and Eichenbaum, Rebelo and Wong (2022).
Q&A
Q1: What is the “rate gap” and why does it capture the cash-out refinance incentive? The rate gap is defined as a borrower’s outstanding fixed mortgage rate minus an estimate of the 30-year fixed mortgage rate currently available to that borrower if they were to refinance (estimated from a regression of origination-period rates on LTV, credit score, loan type, investor type, and month fixed effects). A positive rate gap means the borrower is “in the money” for a rate-term refinance: they can reset their existing mortgage at a lower rate. The rate gap captures the degree of refinance incentive because resets the interest cost on the entire outstanding balance. Cash-out refinancing is especially attractive when the rate gap is positive because the rate reduction on the existing balance partially subsidizes the new borrowing, lowering its effective cost relative to alternative products.
Q2: What is the conceptual model of debt substitution the authors propose? The authors model a homeowner with an inelastic liquidity need l that arrives with probability λ. The borrower can satisfy this need through a cash-out refinance at mortgage rate r_m (resetting their entire mortgage at r_m, which implies an interest cost on the existing balance) or through an alternative product at rate r_a > r_m. The key trade-off is that a cash-out refinance saves on the rate for the liquidity need itself but incurs a cost or benefit depending on whether r_m exceeds or falls below the outstanding rate r_0. When the rate gap is negative (r_0 < r_m), the cash-out refinance penalizes the borrower on the existing balance; when the gap is positive (r_0 > r_m), it saves on the existing balance, further lowering the effective cost of the liquidity need. The model predicts that: (i) the probability of cash-out refinancing is nonlinear and step-like in the rate gap; (ii) the probability of alternative borrowing has the opposite pattern; (iii) higher mortgage rates raise the conditional cash-out amount through selection (low-l borrowers exit cash-out); and (iv) total borrowing is relatively insensitive to mortgage rates.
Q3: How does the Taper Tantrum provide exogenous variation, and what are its limitations? The Taper Tantrum began in late spring 2013 when two FOMC communication events—Chairman Bernanke’s congressional testimony and the subsequent FOMC meeting—shifted market expectations about the pace of tapering large-scale asset purchases (LSAPs). The 30-year fixed mortgage rate rose approximately 80 basis points within one month, driven by changes in long-term rate expectations. Because the shock was unanticipated and FOMC did not announce any concrete policy change, the scope for a “Fed information effect” biasing results is limited. The critical limitation is that the Taper Tantrum affected primarily long-term rates: HELOC rates and consumer credit rates (tied to the federal funds rate and bank prime rate, which were unchanged) were little affected. This means the estimated substitution elasticity holds when the rate spread between mortgage and alternative products widens, which is more directly applicable to unconventional monetary policy (LSAPs) than to conventional policy that moves rates across the full yield curve.
Q4: What do the Taper Tantrum extensive margin results show, and what pattern confirms substitution? Figure 4 plots the difference-in-differences coefficient β₂ + β₃ by pre-Taper rate gap bin for three outcome variables. The cash-out refinancing probability (blue line) declines for all rate gap bins, most sharply for intermediate rate gap values (borrowers pushed out of the money by the Taper). Borrowers with pre-Taper rate gaps of ~1 percent experience a decline in monthly refinancing probability of about 0.0012, or more than 85 percent below their baseline rate. Other borrowing (black line) shows an almost exact mirror-image pattern: it rises after the Taper, most strongly for the same intermediate rate gap borrowers. The total borrowing probability (red line) shows essentially no response and little variation across rate gap groups, implying substitution nearly completely offsets the cash-out decline.
Q5: How do the intensive margin results for cash-out refinancing compare to the extensive margin, and what explains the difference? After the Taper, the conditional cash-out amount rises (the intensive margin effect is positive), while the cash-out probability falls (the extensive margin effect is negative). These opposite signs are consistent with borrower selection: borrowers with small liquidity needs face the steepest increase in effective borrowing cost when they move out of the money and so disproportionately exit cash-out refinancing, raising the average extraction amount among those who remain. For borrowers with pre-Taper rate gaps of ~1 percent, the conditional cash-out amount rises approximately 20 percent after the Taper. Figure 6 corroborates this by showing the increase in average extraction is driven by a sharp decline in small extraction amounts (relative to outstanding balance).
Q6: How is the aggregate borrowing elasticity computed and what does it imply about monetary policy transmission? The authors combine extensive and intensive margin estimates using a two-tiered (hurdle) model that allows the decision to borrow and the decision of how much to borrow to respond differently to covariates. The total expected borrowing amount is the product of the estimated borrowing probability and the expected conditional borrowing amount. Pre- and post-Taper aggregate predicted borrowing is calculated for each rate gap group, and the percentage change is divided by the 80 basis-point rate increase to produce a semi-elasticity. The aggregate borrowing elasticity is not statistically significantly different from zero at the main estimate, and the lower-bound estimate (which avoids reliance on the Post dummy for aggregate borrowing) is at most −8 percent per percentage-point increase in rates. This compares with a cash-out probability elasticity of approximately −45 percent, illustrating that substitution accounts for the overwhelming majority of the observed cash-out response.
Q7: Why is the BRW monetary policy shock IV important for generalizing the Taper Tantrum findings? The Taper Tantrum moved only long rates, whereas conventional monetary policy moves both long and short rates. When short rates rise, the alternative borrowing products (HELOCs, credit cards, personal loans) become more expensive, which could dampen substitution in two ways: (a) the rate spread between mortgage and alternative products narrows, reducing the range of borrower-amount combinations for which substitution makes financial sense; and (b) higher absolute borrowing costs on alternative products may reduce total borrowing among borrowers who would otherwise substitute. The BRW IV, which spans 2006–2021 and reflects shocks to the full yield curve (conventional and unconventional), addresses whether substitution holds when both rate types move. The IV results in Table II (F-statistic ~11) confirm that the cash-out probability elasticity is 3.5 (IV), the other-borrowing elasticity is −0.87 (IV), and the all-borrowing elasticity is 0.09 and statistically insignificant, broadly consistent with the Taper Tantrum findings.
Q8: Does the share of cash-out proceeds used for debt paydown vary with the rate environment, and why does this matter? An event study finds that total household debt increases by about 88 percent of the increase in mortgage balance in the first two months after a cash-out refinance, implying approximately 12 percent debt paydown; by six months out, the net paydown stabilizes at around 8 percent. Crucially, this share is constant across rate gap groups and does not change after the Taper Tantrum. This constancy implies that the marginal propensity to consume (MPC) out of cash-out refinances does not vary with the rate environment, and therefore the path-dependence of the cash-out channel cannot be attributed to compositional changes in how borrowers use extracted funds.
Q9: Why does the paper argue cash-out refinancing has far greater near-term consumption potential than rate-term refinancing, and what are the implications for path dependence? A back-of-the-envelope calculation uses: (1) empirical frequencies (rate-term refinance probability is ~1.5x higher than cash-out); (2) near-term liquidity per event (average first-lien cash-out extraction ~$40,000 vs. annual payment savings ~$3,000 from rate-term); (3) semi-elasticities (rate-term has ~2x higher semi-elasticity to rates than cash-out per the IV estimates); and (4) standard MPC assumptions (100% for cash-out, 80% for rate-term savings). The calculation implies the consumption stimulus potential from cash-out refinancing is approximately 5.5 times that of rate-term refinancing per percentage-point change in rates. Because the paper shows the path-dependence of cash-out refinancing is largely offset by substitution, and because cash-out is the dominant near-term channel, the overall path-dependence of monetary policy is weaker than prior models predict.
Q10: What are the key robustness checks and how do they address potential confounds? Three main robustness exercises are reported. First, a QE1 robustness (Appendix) uses the large decline in mortgage rates after the first LSAP announcement in 2008 as an alternative shock, finding consistent substitution patterns (households shift into cash-out refinancing from other borrowing when pushed into the money). Second, a placebo test shifts the sample back six months and estimates the same specification over the twelve months preceding the Taper; Figure 8 shows no differential substitution by rate gap during this stable-rate period, supporting the interpretation that the Taper Tantrum rate increase drives the cross-sectional substitution pattern. The placebo does reveal a negative Post dummy for other borrowing, consistent with a possible pre-trend in other borrowing, which motivates the lower-bound elasticity calculation that avoids reliance on this coefficient. Third, the authors show that results are little changed when adjustable-rate mortgages (~10 percent of outstanding mortgages in 2013) are included in the sample.
Key Concepts
Rate Gap: The difference between a borrower’s outstanding fixed mortgage rate and the estimated current 30-year fixed mortgage rate available to that borrower if they were to refinance (adjusting for borrower-specific LTV and credit score). A positive rate gap means the borrower is “in the money” for a rate-term refinance. This is the paper’s central measure of refinance incentive, determining whether cash-out refinancing or an alternative borrowing product is the cost-minimizing option for satisfying a given liquidity need.
Debt Substitution: The paper’s core mechanism: households shift their new borrowing across products (cash-out refinance, HELOC, CES, credit card, personal loan) in response to changes in relative borrowing costs, without proportionally changing total new borrowing. When the rate gap is positive, cash-out refinancing is the cheapest way to borrow (it lowers the rate on the existing balance while providing liquidity), so borrowers substitute from alternative products into cash-out. When the rate gap is negative or mortgage rates rise, borrowers substitute in the opposite direction, keeping their original mortgage rate intact by using alternative products.
Cash-Out Refinance Channel of Monetary Policy: The theoretical transmission mechanism by which monetary easing lowers mortgage rates, incentivizes in-the-money borrowers to refinance and extract home equity at reduced cost, and thereby stimulates consumption. Prior literature (Eichenbaum, Rebelo and Wong 2022) treats this channel as path-dependent and quantitatively important because it depends on the distribution of outstanding mortgage rates.
Path Dependence of Monetary Policy: The property by which the same monetary policy shock generates different aggregate borrowing or consumption responses depending on the historical distribution of outstanding fixed mortgage rates, which reflects prior monetary policy. A large share of in-the-money borrowers (due to a prior rate-cutting cycle) amplifies the cash-out refinance channel; a large share of out-of-the-money borrowers weakens it. The paper shows this path dependence is substantially attenuated by debt substitution.
In-the-Money Borrower: A borrower whose outstanding mortgage rate exceeds the current market mortgage rate (positive rate gap), creating a financial incentive to refinance. In-the-money status interacts with borrowing product choice because a cash-out refinance resets the interest cost on the entire existing balance, generating implicit savings that partially subsidize new liquidity extraction.
Hurdle (Two-Tiered) Model: An estimation approach that allows the decision to borrow (extensive margin) and the amount borrowed conditional on borrowing (intensive margin) to respond differently to covariates. The authors use this model to combine extensive and intensive margin estimates into a single aggregate borrowing elasticity, avoiding the distortion that arises from using dollar volume as a dependent variable when intensive and extensive margins have opposite responses to the rate gap.
Taper Tantrum (2013): A quasi-experimental shock used as the paper’s main source of exogenous variation. In late spring 2013, Federal Reserve communications about tapering large-scale asset purchases (LSAPs) caused the 30-year fixed mortgage rate to increase approximately 80 basis points within one month. Because the shock operated through long-term rate expectations, it moved mortgage rates without significantly affecting HELOC or consumer credit rates (tied to the unchanged federal funds and bank prime rates), enabling the authors to estimate substitution holding alternative product rates approximately fixed.