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The perils of credit booms

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Abstract

We present a dynamic general equilibrium model of production economies with adverse selection in the financial market to study the interaction between funding liquidity and market liquidity and its impact on business cycles. Entrepreneurs can take on short-term collateralized debt and trade long-term assets to finance investment. Funding liquidity can erode market liquidity. High funding liquidity discourages firms from selling their good long-term assets since these good assets have to subsidize lemons when there is information asymmetry. This can cause a liquidity dry-up in the market for long-term assets and even a market breakdown, resulting in a financial crisis. Multiple equilibria can coexist. Credit booms combined with changes in beliefs can cause equilibrium regime shifts, leading to an economic crisis or expansion.

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Notes

  1. Our paper is also related to the large literature that studies business cycles with credit market frictions (Kiyotaki and Moore 1997; Carlstrom and Fuerst 1997; Bernanke et al. 1999).

  2. Guerrieri et al. (2010) combine search frictions and adverse selection in a static model.

  3. Other related papers include Eisfeldt (2004), Tomura (2012), Gorton and Ordoñez (2014), Benhabib et al. (2014), Li and Whited (2014), and House and Masatlioglu (2015), among others.

  4. See, e.g., Zhao (2015), Miao et al. (2016), and Ikeda and Phan (2016). Also see Miao (2014) for a survey.

  5. We use Dynare to compute all numerical examples in the paper based on the nonlinear shooting algorithm for solving deterministic dynamic models described in Adjemian et al. (2011).

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Acknowledgements

We are grateful to an anonymous referee for helpful suggestions to improve the paper. We have benefitted from comments by Hengjie Ai, Wei Cui, Zhen Huo, Nicolas Jacquet, Yang Jiao, Benjamin Moll, Nicola Pavoni, Vincenzo Quadrini, Jose-Victor Rios-Rull, Cheng Wang, Yi Wen, Randy Wright, Jianhuan Xu, Tao Zha, Shenghao Zhu, Fabrizio Zilibotti, as well as participants at the NYU Conference on Multiple Equilibria and Financial Crises, the Fourth HKUST International Workshop on Macroeconomics, the 2015 AFR Summer Institute of Economics and Finance at Zhejiang University, the Stockman Conference at University of Rochester, Tsinghua University, Shanghai University of Finance and Economics, Singapore Management University, Renmin University of China, and Peking University.

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Correspondence to Jianjun Miao.

Appendices

Appendix

A Proofs

Proof of Proposition 1

We first consider an entrepreneur’s decision problem. For ease of notation, we suppress the subscript j. Let \(V_{t}\left( k_{t},\varepsilon _{t},h_{t}^{g},h_{t}^{l},b_{t}\right) \) denote the value function, where we have suppressed the aggregate state variables. Then \(V_{t}\) satisfies the following Bellman equation

$$\begin{aligned} V_{t}\left( k_{t},\varepsilon _{t},h_{t}^{g},h_{t}^{l},b_{t}\right) =\max C_{t}+\beta E_{t}V_{t+1}\left( k_{t+1},\varepsilon _{t+1},h_{t+1}^{g},h_{t+1}^{l},b_{t+1}\right) , \quad \end{aligned}$$
(A.1)

subject to the constraints described in Sect. 3, where the conditional expectation is taken with respect to \(\varepsilon _{t+1}\). Conjecture that the value function \(V_{t}\) takes the following form:

$$\begin{aligned} V_{t}\left( k_{t},\varepsilon _{t},h_{t}^{g},h_{t}^{l},b_{t}\right) =q_{t}(\varepsilon _{t})k_{t}+\phi _{t}^{g}(\varepsilon _{t})h_{t}^{g}+\phi _{t}^{l}(\varepsilon _{t})h_{t}^{l}+\phi _{t}^{b}\left( \varepsilon _{t}\right) b_{t}, \end{aligned}$$
(A.2)

where \(q_{t}(\varepsilon _{t}),\) \(\phi _{t}^{g}(\varepsilon _{t}),\) \(\phi _{t}^{l}(\varepsilon _{t}),\) and \(\phi _{t}^{b}(\varepsilon _{t})\) are to be determined.

Then \(V_{t+1}\) is also linear and we can write

$$\begin{aligned} \beta E_{t}\left[ V_{t+1}\left( k_{t+1},\varepsilon _{t+1},h_{t+1}^{g},h_{t+1}^{l},b_{t+1}\right) \right] =Q_{t}k_{t+1}+p_{t}^{g}h_{t+1}^{g}+p_{t}^{l}h_{t+1}^{l}+p_{t}^{b}b_{t+1} , \end{aligned}$$

where we define

$$\begin{aligned} Q_{t}= & {} \beta E\left[ q_{t+1}(\varepsilon _{t+1})\right] , \ p_{t}^{g}=\beta E\left[ \phi _{t+1}^{g}(\varepsilon _{t+1})\right] , \end{aligned}$$
(A.3)
$$\begin{aligned} p_{t}^{l}= & {} \beta E\left[ \phi _{t+1}^{l}(\varepsilon _{t+1})\right] , \ p_{t}^{b}=\beta E\left[ \phi _{t+1}^{b}\left( \varepsilon _{t+1}\right) \right] . \end{aligned}$$
(A.4)

We use the flow-of-funds constraint and other constraints in Sect. 3 to derive

$$\begin{aligned}&C_{\textit{jt}}+\beta E_{t}V_{t+1}\left( k_{t+1},\varepsilon _{t+1},h_{t+1}^{g},h_{t+1}^{l},b_{t+1}\right) \\&\quad =R_{kt}k_{t}+P_{t}^{g}\left( s_{t}^{g}-x_{t}^{g}\right) +P_{t}^{l}\left( s_{t}^{l}-x_{t}^{l}\right) +ch_{t}^{g}+b_{t} \\&\qquad -i_{t}-\frac{b_{t+1}}{R_{\textit{ft}}} +Q_{t}k_{t+1}+p_{t}^{g}h_{t+1}^{g}+p_{t}^{l}h_{t+1}^{l}+p_{t}^{b}b_{t+1} \\&\quad =R_{kt}k_{t}-i_{t}+P_{t}^{g}\left( s_{t}^{g}-x_{t}^{g}\right) +P_{t}^{l}\left( s_{t}^{l}-x_{t}^{l}\right) +ch_{t}^{g}-\frac{b_{t+1}}{R_{\textit{ft}} }+b_{t} \\&\qquad +Q_{t}\left[ \left( 1-\delta \right) k_{t}+i_{t}\varepsilon _{t}\right] +p_{t}^{g}\left( h_{t}^{g}-s_{t}^{g}+x_{t}^{g}\right) +p_{t}^{l}\left( h_{t}^{l}-s_{t}^{l}+x_{t}^{l}\right) +p_{t}^{b}b_{t+1} \\&\quad =\left[ R_{kt}+\left( 1-\delta \right) Q_{t}\right] k_{t}+\left( p_{t}^{g}+c\right) h_{t}^{g}+p_{t}^{l}h_{t}^{l}+b_{t}+\left( p_{t}^{b}-\frac{ 1}{R_{\textit{ft}}}\right) b_{t+1} \\&\qquad +\left( Q_{t}\varepsilon _{t}-1\right) i_{t}+\left( p_{t}^{g}-P_{t}^{g}\right) x_{t}^{g}+\left( p_{t}^{l}-P_{t}^{l}\right) x_{t}^{l}+\left( P_{t}^{g}-p_{t}^{g}\right) s_{t}^{g}+\left( P_{t}^{l}-p_{t}^{l}\right) s_{t}^{l}. \end{aligned}$$

If \(p_{t}^{g}>P_{t}^{g},\) then all entrepreneurs would purchase as much good assets as possible. If \(p_{t}^{g}<P_{t}^{g},\) then no entrepreneurs would purchase any good asset. In both cases a competitive equilibrium could not exist. Thus we must have \(p_{t}^{g}=P_{t}^{g}\) and \(p_{t}^{l}=P_{t}^{l}\). If \(p_{t}^{b}>1/R_{\textit{ft}},\) then all entrepreneurs would prefer to buy bonds and an equilibrium could not exist. If \(p_{t}^{b}<1/R_{\textit{ft}},\) then all entrepreneurs would borrow until the borrowing constraint binds. In this case all entrepreneurs would also want to purchase as much financial assets as possible in order to take leverage. But this would not constitute an equilibrium. Thus \(1/R_{\textit{ft}}=p_{t}^{b}.\)

We can simplify the last equality to derive

$$\begin{aligned}&C_{t}+\beta E_{t}V_{t+1}\left( k_{t+1},\varepsilon _{t+1},h_{t+1}^{g},h_{t+1}^{l},b_{t+1}\right) \\&\quad =\left[ R_{kt}+\left( 1-\delta \right) Q_{t}\right] k_{t}+\left( P_{t}^{g}+c\right) h_{t}^{g}+P_{t}^{l}h_{t}^{l}+b_{t}+\left( Q_{t}\varepsilon _{t}-1\right) i_{t}. \end{aligned}$$

Let \(\varepsilon _{t}^{*}=1/Q_{t}\). Since \(i_{t}\ge 0,\) it is optimal to make as much investment as possible if and only if \(\varepsilon _{t}\ge \varepsilon _{t}^{*}.\)

By the flow-of-funds constraint and the borrowing constraint,

$$\begin{aligned} i_{t}= & {} R_{kt}k_{t}+P_{t}^{g}\left( s_{t}^{g}-x_{t}^{g}\right) +P_{t}^{l}\left( s_{t}^{l}-x_{t}^{l}\right) +ch_{t}^{g}+b_{t}-C_{t}-\frac{ b_{t+1}}{R_{\textit{ft}}} \\\le & {} R_{kt}k_{t}+P_{t}^{g}s_{t}^{g}+P_{t}^{l}s_{t}^{l}-\left( P_{t}^{g}x_{t}^{g}+P_{t}^{l}x_{t}^{l}\right) +\mu _{t}k_{t}+ch_{t}^{g}+b_{t}. \end{aligned}$$

Since a firm with \(\varepsilon _{t}>\varepsilon _{t}^{*}\) wants to invest using as many resources as possible, it will not purchase any asset and will sell all its assets; that is

$$\begin{aligned} x_{t}^{g}=x_{t}^{l}=0, \ s_{t}^{g}=h_{t}^{g},\, s_{t}^{l}=h_{t}^{l}. \end{aligned}$$

Moreover, it will borrow as much as possible up to the borrowing limit. A firm with \(\varepsilon _{t}<\varepsilon _{t}^{*}\) will not invest. Since \(p_{t}^{b}=1/R_{\textit{ft}}\), \(p_{t}^{l}=P_{t}^{l},\) and \(p_{t}^{g}=P_{t}^{g},\) the firm is indifferent between saving and borrowing and is indifferent between buying and selling assets. We then obtain the optimal investment rule

$$\begin{aligned} i_{t}=\left\{ \begin{array}{c@{\quad }c} R_{kt}k_{t}+\left( P_{t}^{g}+c\right) h_{t}^{g}+P_{t}^{l}h_{t}^{l}+\mu _{t}k_{t}+b_{t} &{} \text {if }\varepsilon _{t}>\varepsilon _{t}^{*}\, \\ 0 &{} \text {otherwise} \end{array} \right. . \end{aligned}$$

Thus we can derive aggregate investment and the law of motion for capital in Eqs. (20) and (21), where we have used the market-clearing condition for bonds, i.e., \(\int b_{\textit{jt}}\mathrm{d}j=0\).

Substituting the decision rules back into (A.1) and using the conjectured value function, we can derive

$$\begin{aligned}&q_{t}(\varepsilon _{t})k_{t}+\phi _{t}^{g}(\varepsilon _{t})h_{t}^{g}+\phi _{t}^{l}(\varepsilon _{t})h_{t}^{l}+\phi _{t}^{b}\left( \varepsilon _{t}\right) b_{t} \\&\quad =\left[ \left( 1-\delta \right) Q_{t}+R_{kt}\right] k_{t}+\left( P_{t}^{g}+c\right) h_{t}^{g}+P_{t}^{l}h_{t}^{l}+b_{t} \\&\qquad +\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}}-1,0\right) \left[ R_{kt}k_{t}+\left( P_{t}^{g}+c\right) h_{t}^{g}+P_{t}^{l}h_{t}^{l}+b_{t}+\mu _{t}k_{t}\right] \\&\quad =\left\{ \left( 1-\delta \right) Q_{t}+R_{kt}\left[ 1+\max \left( \frac{ \varepsilon _{t}}{\varepsilon _{t}^{*}}-1,0\right) \right] +\mu _{t}\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}}-1,0\right) \right\} k_{t} \\&\qquad +\left( P_{t}^{g}+c\right) \left[ 1+\max \left( \frac{\varepsilon _{t}}{ \varepsilon _{t}^{*}}-1,0\right) \right] h_{t}^{g} \\&\qquad +P_{t}^{l}\left[ 1+\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}}-1,0\right) \right] h_{t}^{l}+\left[ 1+\max \left( \frac{ \varepsilon _{t}}{\varepsilon _{t}^{*}}-1,0\right) \right] b_{t}. \end{aligned}$$

Matching coefficients yields

$$\begin{aligned} q_{t}(\varepsilon _{t})= & {} \left( 1-\delta \right) Q_{t}+R_{kt}\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}},1\right) +\mu _{t}\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}}-1,0\right) , \\ \phi _{t}^{g}(\varepsilon _{t})= & {} \left( P_{t}^{g}+c\right) \left[ 1+\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}}-1,0\right) \right] , \\ \phi _{t}^{l}(\varepsilon _{t})= & {} P_{t}^{l}\left[ 1+\max \left( \frac{ \varepsilon _{t}}{\varepsilon _{t}^{*}}-1,0\right) \right] , \\ \phi _{t}^{b}\left( \varepsilon _{t}\right)= & {} 1+\max \left( \frac{ \varepsilon _{t}}{\varepsilon _{t}^{*}}-1,0\right) . \end{aligned}$$

Using the preceding definition of \(Q_{t},\) \(p_{t}^{g},p_{t}^{l}\) and \( p_{t}^{b}\) and noting that \(p_{t}^{g}=P_{t}^{g}\), \(p_{t}^{l}=P_{t}^{l},\) \( p_{t}^{b}=1/R_{\textit{ft}},\) we can derive their asset pricing equations given in Proposition 1.

Since firms with \(\varepsilon _{t}\le \varepsilon _{t}^{*}\) are indifferent between buying and selling assets, we allow them to purchase assets so that asset markets can clear

$$\begin{aligned} \int _{\varepsilon _{t}\le \varepsilon _{t}^{*}}x_{t}^{g}\left( \varepsilon _{t}\right) \mathrm{d}F\left( \varepsilon \right)= & {} \left[ 1-F\left( \varepsilon _{t}^{*}\right) \right] \left( 1-\pi \right) , \\ \int _{\varepsilon _{t}\le \varepsilon _{t}^{*}}x_{t}^{l}\left( \varepsilon _{t}\right) \mathrm{d}F\left( \varepsilon \right)= & {} \left[ 1-F\left( \varepsilon _{t}^{*}\right) \right] \pi . \end{aligned}$$

Without loss of generality, we can set individual purchasing choice as

$$\begin{aligned} x_{t}^{g}=\left\{ \begin{array}{c@{\quad }c} \frac{\left[ 1-F\left( \varepsilon _{t}^{*}\right) \right] \left( 1-\pi \right) }{F\left( \varepsilon _{t}^{*}\right) } &{} \text {if }\varepsilon _{t}<\varepsilon _{t}^{*}\, \\ 0 &{} \text {otherwise} \end{array} \right. ,\,x_{t}^{l}=\left\{ \begin{array}{c@{\quad }c} \frac{\left[ 1-F\left( \varepsilon _{t}^{*}\right) \right] \pi }{F\left( \varepsilon _{t}^{*}\right) } &{} \text {if }\varepsilon _{t}<\varepsilon _{t}^{*}\, \\ 0 &{} \text {otherwise} \end{array} \right. . \end{aligned}$$

Moreover firms with \(\varepsilon _{t}<\varepsilon _{t}^{*}\) are indifferent between saving and borrowing. \(\square \)

Proof of Lemma 1

It is straightforward to check that \(\beta \left[ 1+\int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\left( \frac{\varepsilon }{\varepsilon ^{*}} -1\right) \mathrm{d}F\left( \varepsilon \right) \right] \) decreases with \(\varepsilon ^{*}\). Since

$$\begin{aligned} \beta \left[ 1+\int _{\varepsilon _{\max }}^{\varepsilon _{\max }}\left( \frac{\varepsilon }{\varepsilon _{\max }}-1\right) \mathrm{d}F\left( \varepsilon \right) \right] =\beta <1,\, \beta \left[ 1+\int _{\varepsilon _{\min }}^{\varepsilon _{\max }}\left( \frac{\varepsilon }{\varepsilon _{\min }} -1\right) \mathrm{d}F\left( \varepsilon \right) \right] >1, \end{aligned}$$

where the second inequality comes from Assumption 1, it follows from the intermediate value theorem that there exists a unique solution, denoted by \( \varepsilon _{b}^{*}\in \left( \varepsilon _{\min },\varepsilon _{\max }\right) ,\) to the equation \(\beta \left[ 1+\int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\left( \frac{\varepsilon }{\varepsilon ^{*}} -1\right) \mathrm{d}F\left( \varepsilon \right) \right] =1\). \(\square \)

Proof of Proposition 2:

Equation (17) in the steady state gives (26). For \( P^{g}>0,\) we need

$$\begin{aligned} \frac{1}{R_{f}}=\beta \left[ 1+\int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\left( \frac{\varepsilon }{\varepsilon ^{*}}-1\right) \mathrm{d}F\left( \varepsilon \right) \right] <1. \end{aligned}$$

If follows from Eq. (18) that \(P^{l}=0\). By Lemma 1, the condition above is equivalent to \(\varepsilon ^{*}>\varepsilon _{b}^{*}\). Using \(Q=1/\varepsilon ^{*}\) and Eq. (16), we can derive the steady-state capital stock in Eq. (27). Using Eq. (20) in the steady state yields

$$\begin{aligned} \delta K=\left[ \alpha AK^{\alpha }+\mu K+\left( 1-\pi \right) \left( P^{g}+c\right) \right] \int _{\varepsilon ^{*}}^{\varepsilon ^{\max }}\varepsilon \mathrm{d}F(\varepsilon ). \end{aligned}$$

Substituting (26) for \(P^{g}\) and (27) for \(K=K\left( \varepsilon ^{*}\right) \) into the equation above gives an equation for \( \varepsilon ^{*},\) (28). We need the following lemma to complete the proof.

Lemma 3

For a sufficiently small \(\mu \), \(K\left( \varepsilon ^{*}\right) \) increases with \(\varepsilon ^{*}\) on \(\left( \varepsilon _{\min },\varepsilon _{\max }\right) .\)

Proof

Let

$$\begin{aligned} h\left( \varepsilon ^{*}\right) =\frac{1/\beta -1+\delta -\mu \int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\left( \varepsilon -\varepsilon ^{*}\right) \mathrm{d}F\left( \varepsilon \right) }{\varepsilon ^{*}+\int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\left( \varepsilon -\varepsilon ^{*}\right) \mathrm{d}F\left( \varepsilon \right) }. \end{aligned}$$

We can compute that

$$\begin{aligned} h^{\prime }\left( \varepsilon ^{*}\right) =\frac{\mu \left[ \left( 1-F\left( \varepsilon ^{*}\right) \right) \varepsilon ^{*}+\int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\left( \varepsilon -\varepsilon ^{*}\right) \mathrm{d}F\left( \varepsilon \right) \right] -F\left( \varepsilon ^{*}\right) \left( 1/\beta -1+\delta \right) }{\left[ \varepsilon ^{*}+\int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\left( \varepsilon -\varepsilon ^{*}\right) \mathrm{d}F\left( \varepsilon \right) \right] ^{2}}. \end{aligned}$$

For a sufficiently small \(\mu \in \left( \varepsilon _{\min },\varepsilon _{\max }\right) ,\) \(h^{\prime }\left( \varepsilon ^{*}\right) <0.\) Thus by (27),

$$\begin{aligned} K\left( \varepsilon ^{*}\right) =\left[ \frac{h\left( \varepsilon ^{*}\right) }{\alpha A}\right] ^{\frac{1}{\alpha -1}} \end{aligned}$$

increases with \(\varepsilon ^{*}.\) \(\square \)

Simple algebra shows that the expression

$$\begin{aligned}&\frac{\delta }{\int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\varepsilon \mathrm{d}F\left( \varepsilon \right) }-\alpha AK\left( \varepsilon ^{*}\right) ^{\alpha -1}-\mu =\frac{\delta }{\int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\varepsilon \mathrm{d}F\left( \varepsilon \right) }\\&\qquad -\frac{\left( \frac{1}{ \beta }-1+\delta \right) \frac{1}{\varepsilon ^{*}}-\mu \int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\left( \frac{\varepsilon }{ \varepsilon ^{*}}-1\right) \mathrm{d}F\left( \varepsilon \right) }{ 1+\int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\left( \frac{\varepsilon }{\varepsilon ^{*}}-1\right) \mathrm{d}F\left( \varepsilon \right) }-\mu \end{aligned}$$

increases with \(\varepsilon ^{*}\) on \(\left( \varepsilon _{b}^{*},\varepsilon _{\max }\right) .\) Let \(D\left( \varepsilon ^{*}\right) \) denote the expression on the left-hand side of (28). Then since \(D\left( \varepsilon ^{*}\right) \) is the product of the preceding expression and \(K\left( \varepsilon ^{*}\right) \), it increases with \( \varepsilon ^{*}.\)

We can check that

$$\begin{aligned} S\left( \varepsilon ^{*}\right) \equiv \frac{\left( 1-\pi \right) c}{ R_{f}\left( \varepsilon ^{*}\right) -1} \end{aligned}$$

decreases with \(\varepsilon ^{*}\) on \(\left( \varepsilon _{b}^{*},\varepsilon _{\max }\right) .\) As \(\varepsilon ^{*}\) decreases to \( \varepsilon _{b}^{*},\ S\left( \varepsilon ^{*}\right) \) approaches infinity since \(R_{f}\left( \varepsilon _{b}^{*}\right) =1\) by Lemma 1, but \(D\left( \varepsilon _{b}^{*}\right) \) is finite. As \(\varepsilon ^{*}\) increases to \(\varepsilon _{\max },\) \(D\left( \varepsilon ^{*}\right) \) approaches infinity, but the limit of \(S\left( \varepsilon ^{*}\right) \) is finite. By the intermediate value theorem, there is a unique solution to \(\varepsilon ^{*}\in \left( \varepsilon _{b}^{*},\varepsilon _{\max }\right) \) in Eq. (28).

Differentiating the expressions on the two sides of Eq. (28) yields

$$\begin{aligned} \frac{\partial D\left( \varepsilon ^{*}\right) }{\partial \varepsilon ^{*}}\frac{\partial \varepsilon ^{*}}{\partial \mu }-K\left( \varepsilon ^{*}\right) =\frac{\partial S\left( \varepsilon ^{*}\right) }{\partial \varepsilon ^{*}}\frac{\partial \varepsilon ^{*} }{\partial \mu }. \end{aligned}$$

We then have

$$\begin{aligned} \frac{\partial \varepsilon ^{*}}{\partial \mu }\left[ \frac{\partial D\left( \varepsilon ^{*}\right) }{\partial \varepsilon ^{*}}-\frac{ \partial S\left( \varepsilon ^{*}\right) }{\partial \varepsilon ^{*}} \right] =K\left( \varepsilon ^{*}\right) . \end{aligned}$$

Since \(\frac{\partial D\left( \varepsilon ^{*}\right) }{\partial \varepsilon ^{*}}>0\) and \(\frac{\partial S\left( \varepsilon ^{*}\right) }{\partial \varepsilon ^{*}}<0\) for small \(\mu ,\) we have \( \frac{\partial \varepsilon ^{*}}{\partial \mu }>0.\) Since \(K\left( \varepsilon ^{*}\right) \) and \(R_{f}\left( \varepsilon ^{*}\right) \) increase with \(\varepsilon ^{*}\), Y increases with \(\mu \) and \(P^{g}\) decreases with \(\mu .\) \(\square \)

Proof of Proposition 3:

We can write down an entrepreneur’s decision problem by dynamic programming as in (A.1) subject to the constraints given in Sect. 2. We suppress the subscript j throughout the proof. Conjecture that the value function takes the form as in (A.2). Then we have

$$\begin{aligned} \beta E\left[ V_{t+1}(k_{t+1},\varepsilon _{t+1},h_{t+1}^{g},h_{t+1}^{l},b_{t+1})\right] =Q_{t}k_{t+1}+p_{t}^{g}h_{t+1}^{g}+p_{t}^{l}h_{t+1}^{l}+p_{t}^{b}b_{t+1} , \end{aligned}$$

where \(Q_{t},\) \(p_{t}^{g},\) \(P_{t}^{l},\) and \(p_{t}^{b}\) are defined as in (A.3) and (A.4).

Using the flow-of-funds constraint and the preceding equation, we can derive

$$\begin{aligned}&C_{t}+\beta E_{t}V_{t+1}\left( k_{t+1},\varepsilon _{t+1},h_{t+1}^{g},h_{t+1}^{l},b_{t+1}\right) \\&\quad =R_{kt}k_{t}-i_{t}+P_{t}\left( s_{t}^{g}+s_{t}^{l}-x_{t}\right) +ch_{t}^{g}-\frac{b_{t+1}}{R_{\textit{ft}}}+b_{t} \\&\qquad +Q_{t}k_{t+1}+p_{t}^{g}h_{t+1}^{g}+p_{t}^{l}h_{t+1}^{l}+p_{t}^{b}b_{t+1} \\&\quad =R_{kt}k_{t}-i_{t}+P_{t}\left( s_{t}^{g}+s_{t}^{l}-x_{t}\right) +ch_{t}^{g}-\frac{b_{t+1}}{R_{\textit{ft}}}+b_{t} \\&\qquad +Q_{t}\left[ \left( 1-\delta \right) k_{t}+i_{t}\varepsilon _{t}\right] +p_{t}^{g}\left( \varTheta _{t}x_{t}+h_{t}^{g}-s_{t}^{g}\right) \\&\qquad +p_{t}^{l}\left[ \left( 1-\varTheta _{t}\right) x_{t}+h_{t}^{l}-s_{t}^{l} \right] +p_{t}^{b}b_{t+1}\\&\quad =\left[ \left( 1-\delta \right) Q_{t}+R_{kt}\right] k_{t}+\left( p_{t}^{g}+c\right) h_{t}^{g}+p_{t}^{l}h_{t}^{l} \\&\qquad +\left( Q_{t}\varepsilon _{t}-1\right) i_{t}+\left[ \varTheta _{t}p_{t}^{g}+\left( 1-\varTheta _{t}\right) p_{t}^{l}-P_{t}\right] x_{t} \\&\qquad +\left( P_{t}-p_{t}^{g}\right) s_{t}^{g}+\left( P_{t}-p_{t}^{l}\right) s_{t}^{l}+b_{t}+\left( p_{t}^{b}-\frac{1}{R_{\textit{ft}}}\right) b_{t+1}. \end{aligned}$$

By a similar argument to the proof of Proposition 1, for the entrepreneur’s optimal decisions to be compatible with a competitive equilibrium, we must have

$$\begin{aligned} P_{t}=\varTheta _{t}p_{t}^{g}+(1-\varTheta _{t})p_{t}^{l}, \ p_{t}^{b}= \frac{1}{R_{\textit{ft}}}. \end{aligned}$$

Thus we have

$$\begin{aligned}&\max _{i_{t},s_{t}^{l},s_{t}^{g},x_{t},C_{t},b_{t+1}}\, C_{t}+\beta E_{t}V_{t+1}\left( k_{t+1},\varepsilon _{t+1},h_{t+1}^{g},h_{t+1}^{l},b_{t+1}\right) \\&\quad =\max _{i_{t},s_{t}^{l},s_{t}^{g}}\, \left[ \left( 1-\delta \right) Q_{t}+R_{kt}\right] k_{t}+\left( p_{t}^{g}+c\right) h_{t}^{g}+p_{t}^{l}h_{t}^{l}+b_{t} \\&\qquad +\left( Q_{t}\varepsilon _{t}-1\right) i_{t}+\left( P_{t}-p_{t}^{g}\right) s_{t}^{g}+\left( P_{t}-p_{t}^{l}\right) s_{t}^{l}. \end{aligned}$$

Since \(i_{t}\ge 0,\) it is optimal for the firm to make real investment if and only if \(\varepsilon _{t}\ge 1/Q_{t}=\varepsilon _{t}^{*}.\) When making the investment, the firm will invest as much as possible. By the flow-of-funds constraint (6) and the borrowing constraint (7), we have

$$\begin{aligned} i_{t}= & {} R_{kt}k_{t}+P_{t}\left( s_{t}^{g}+s_{t}^{l}\right) -P_{t}x_{t}+ch_{t}^{g}+b_{t}-C_{t}-\frac{b_{t+1}}{R_{\textit{ft}}} \\\le & {} R_{kt}k_{t}+P_{t}\left( s_{t}^{g}+s_{t}^{l}\right) +ch_{t}^{g}+b_{t}+\mu _{t}k_{t}-P_{t}x_{t}. \end{aligned}$$

To leave the maximum resource for investing, the firm will not purchase any asset; that is, \(x_{t}=0.\) The borrowing constraint must also bind when \( \varepsilon _{t}>1/Q_{t}=\varepsilon _{t}^{*}.\) Thus we obtain the investment rule

$$\begin{aligned} i_{t}=\left\{ \begin{array}{c@{\quad }c} R_{kt}k_{t}+P_{t}\left( s_{t}^{g}+s_{t}^{l}\right) +ch_{t}^{g}+b_{t}+\mu _{t}k_{t} &{} \text {for }\varepsilon _{t}\ge \varepsilon _{t}^{*} \\ 0 &{} \varepsilon _{t}<\varepsilon _{t}^{*} \end{array} \right. . \end{aligned}$$

Substituting this investment rule into the right-hand side of the Bellman equation in (A.1), we can derive that for \(\varepsilon _{t}>\varepsilon _{t}^{*},\)

$$\begin{aligned}&\max _{i_{t},s_{t}^{l},s_{t}^{g},x_{t},C_{t},b_{t+1}}\, C_{t}+\beta E_{t}V_{t+1}\left( k_{t+1},\varepsilon _{t+1},h_{t+1}^{g},h_{t+1}^{l},b_{t+1}\right) \\&\quad =\max _{s_{t}^{l},s_{t}^{g}}\, \left[ \left( 1-\delta \right) Q_{t}+R_{kt}\right] k_{t}+\left( p_{t}^{g}+c\right) h_{t}^{g}+p_{t}^{l}h_{t}^{l}+b_{t} \\&\qquad +\left( Q_{t}\varepsilon _{t}-1\right) \left[ R_{kt}k_{t}+P_{t}\left( s_{t}^{g}+s_{t}^{l}\right) +ch_{t}^{g}+b_{t}+\mu _{t}k_{t}\right] \\&\qquad +\left( P_{t}-p_{t}^{g}\right) s_{t}^{g}+\left( P_{t}-p_{t}^{l}\right) s_{t}^{l} \\&\quad =\max _{s_{t}^{l},s_{t}^{g}}\, \left[ \left( 1-\delta \right) Q_{t}+Q_{t}\varepsilon _{t}R_{kt}+\mu _{t}\left( Q_{t}\varepsilon _{t}-1\right) \right] k_{t}+\left( p_{t}^{g}+Q_{t}\varepsilon _{t}c\right) h_{t}^{g}+p_{t}^{l}h_{t}^{l} \\&\qquad +Q_{t}\varepsilon _{t}b_{t}+\left( Q_{t}\varepsilon _{t}P_{t}-p_{t}^{g}\right) s_{t}^{g}+\left( Q_{t}\varepsilon _{t}P_{t}-p_{t}^{l}\right) s_{t}^{l} \\&\quad =\, \left[ \left( 1-\delta \right) Q_{t}+Q_{t}\varepsilon _{t}R_{kt}+\mu _{t}\left( Q_{t}\varepsilon _{t}-1\right) \right] k_{t}+Q_{t}P_{t}\varepsilon _{t}h_{t}^{l}+Q_{t}\varepsilon _{t}b_{t} \\&\qquad +\left[ p_{t}^{g}+Q_{t}\varepsilon _{t}c+\max \left( Q_{t}P_{t}\varepsilon _{t}-p_{t}^{g},0\right) \right] h_{t}^{g}, \end{aligned}$$

where in the last equality we have used the fact that \(s_{t}^{l}=h_{t}^{l}\) since \(Q_{t}\varepsilon _{t}P_{t}\ge P_{t}\ge p_{t}^{l}\) and that \( s_{t}^{g}=h_{t}^{g}\) if \(Q_{t}P_{t}\varepsilon _{t}\ge p_{t}^{g}\) and \( s_{t}^{g}=0,\) otherwise.

If \(\varepsilon _{t}\le \varepsilon _{t}^{*}\), then \(i_{t}=0\) and we have

$$\begin{aligned}&\max _{i_{t},s_{t}^{l},s_{t}^{g},x_{t},C_{t},b_{t+1}}\, C_{t}+\beta E_{t}V_{t+1}\left( k_{t+1},\varepsilon _{t+1},h_{t+1}^{g},h_{t+1}^{l},b_{t+1}\right) \\&\quad =\max _{s_{t}^{g},s_{t}^{l}}\, \left[ \left( 1-\delta \right) Q_{t}+R_{kt}\right] k_{t}+\left( p_{t}^{g}+c\right) h_{t}^{g}+p_{t}^{l}h_{t}^{l}+b_{t} \\&\qquad +\left( P_{t}-p_{t}^{g}\right) s_{t}^{g}+\left( P_{t}-p_{t}^{l}\right) s_{t}^{l} \\&\quad =\left[ \left( 1-\delta \right) Q_{t}+R_{kt}\right] k_{t}+\left( p_{t}^{g}+c\right) h_{t}^{g}+P_{t}h_{t}^{l}+b_{t}, \end{aligned}$$

where the second equality follows from the fact that \(s_{t}^{g}=0\) since \( P_{t}\le p_{t}^{g}\) and that \(s_{t}^{l}=h_{t}^{l}\) since \(P_{t}\ge p_{t}^{l}.\)

We now combine the preceding two cases for all \(\varepsilon _{t}\in \left[ \varepsilon _{\min },\varepsilon _{\max }\right] \). If

$$\begin{aligned} P_{t}\ge \frac{p_{t}^{g}}{Q_{t}\varepsilon _{\max }}=\frac{\varepsilon _{t}^{*}}{\varepsilon _{\max }}p_{t}^{g}, \end{aligned}$$

then

$$\begin{aligned}&\max _{i_{t},s_{t}^{l},s_{t}^{g},x_{t},C_{t},b_{t+1}}C_{t}+\beta E_{t}V_{t+1}\left( k_{t+1},\varepsilon _{t+1},h_{t+1}^{g},h_{t+1}^{l},b_{t+1}\right) \\&\quad =\left[ \left( 1-\delta \right) Q_{t}+\max \left( \frac{\varepsilon _{t}}{ \varepsilon _{t}^{*}},1\right) R_{kt}+\max \left( \frac{\varepsilon _{t} }{\varepsilon _{t}^{*}}-1,0\right) \mu _{t}\right] k_{t} \\&\qquad +\left[ p_{t}^{g}+\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}},1\right) c+Q_{t}P_{t}\max \left( \varepsilon _{t}-\frac{ p_{t}^{g}}{p_{t}Q_{t}},0\right) \right] h_{t}^{g} \\&\qquad +\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}},1\right) P_{t}h_{t}^{l}+\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}} ,1\right) b_{t} \\&\quad =\left[ \left( 1-\delta \right) Q_{t}+\max \left( \frac{\varepsilon _{t}}{ \varepsilon _{t}^{*}},1\right) R_{kt}+\max \left( \frac{\varepsilon _{t} }{\varepsilon _{t}^{*}}-1,0\right) \mu _{t}\right] k_{t} \\&\qquad +\left[ \max \left( \frac{\varepsilon _{t}}{p_{t}^{g}/\left( P_{t}Q_{t}\right) },1\right) p_{t}^{g}+\max \left( \frac{\varepsilon _{t}}{ \varepsilon _{t}^{*}},1\right) c\right] h_{t}^{g} \\&\qquad +\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}},1\right) P_{t}h_{t}^{l}+\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}} ,1\right) b_{t}. \end{aligned}$$

If

$$\begin{aligned} P_{t}<\frac{p_{t}^{g}}{Q_{t}\varepsilon _{\max }}=\frac{\varepsilon _{t}^{*}}{\varepsilon _{\max }}p_{t}^{g}, \end{aligned}$$

then

$$\begin{aligned}&\max _{i_{t},s_{t}^{l},s_{t}^{g},x_{t},C_{t},b_{t+1}}\, C_{t}+\beta E_{t}V_{t+1}\left( k_{t+1},\varepsilon _{t+1},h_{t+1}^{g},h_{t+1}^{l},b_{t+1}\right) \\&\quad =\left[ \left( 1-\delta \right) Q_{t}+\max \left( \frac{\varepsilon _{t}}{ \varepsilon _{t}^{*}},1\right) R_{kt}+\max \left( \frac{\varepsilon _{t} }{\varepsilon _{t}^{*}}-1,0\right) \mu _{t}\right] k_{t} \\&\qquad +\left[ p_{t}^{g}+\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}},1\right) c\right] h_{t}^{g}+\max \left( \frac{\varepsilon _{t} }{\varepsilon _{t}^{*}},1\right) P_{t}h_{t}^{l}+\max \left( \frac{ \varepsilon _{t}}{\varepsilon _{t}^{*}},1\right) b_{t} \\&\quad =\left[ \left( 1-\delta \right) Q_{t}+\max \left( \frac{\varepsilon _{t}}{ \varepsilon _{t}^{*}},1\right) R_{kt}+\max \left( \frac{\varepsilon _{t} }{\varepsilon _{t}^{*}}-1,0\right) \mu _{t}\right] k_{t} \\&\qquad +\left[ \max \left( \frac{\varepsilon _{t}}{\varepsilon ^{\max }},1\right) p_{t}^{g}+\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}} ,1\right) c\right] h_{t}^{g}+\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}},1\right) P_{t}h_{t}^{l}\\&\qquad +\max \left( \frac{\varepsilon _{t}}{ \varepsilon _{t}^{*}},1\right) b_{t}. \end{aligned}$$

Let \(\varepsilon _{t}^{**}\equiv \min \left( \frac{p_{t}^{g}}{ P_{t}Q_{t}},\varepsilon ^{\max }\right) .\) Then for any \(\varepsilon _{t}\in \left( \varepsilon ^{\min },\varepsilon ^{\max }\right) \), we can write

$$\begin{aligned}&\max _{i_{t},s_{t}^{l},s_{t}^{g},x_{t},C_{t},b_{t+1}}C_{t}+\beta E_{t}V_{t+1}\left( k_{t+1},\varepsilon _{t+1},h_{t+1}^{g},h_{t+1}^{l},b_{t+1}\right) \\&\quad =\left[ \left( 1-\delta \right) Q_{t}+\max \left( \frac{\varepsilon _{t}}{ \varepsilon _{t}^{*}},1\right) R_{kt}+\max \left( \frac{\varepsilon _{t} }{\varepsilon _{t}^{*}}-1,0\right) \mu _{t}\right] k_{t}\\&\qquad +\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}},1\right) P_{t}h_{t}^{l} \\&\qquad +\left[ \max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{**}} ,1\right) p_{t}^{g}+\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}},1\right) c\right] h_{t}^{g}+\max \left( \frac{\varepsilon _{t} }{\varepsilon _{t}^{*}},1\right) b_{t}. \end{aligned}$$

Substituting the preceding equation into the Bellman equation and using (A.2), we match coefficients to derive that for any \(\varepsilon _{t}\in \left( \varepsilon _{\min },\varepsilon _{\max }\right) \),

$$\begin{aligned} q_{t}(\varepsilon _{t})= & {} \left( 1-\delta \right) Q_{t}+\max \left( \frac{ \varepsilon _{t}}{\varepsilon _{t}^{*}},1\right) R_{kt}+\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}}-1,0\right) \mu _{t}, \\ \phi _{t}^{g}(\varepsilon _{t})= & {} \max \left( \frac{\varepsilon _{t}}{ \varepsilon _{t}^{**}},1\right) p_{t}^{g}+\max \left( \frac{ \varepsilon _{t}}{\varepsilon _{t}^{*}},1\right) c, \\ \phi _{t}^{l}(\varepsilon _{t})= & {} \max \left( \frac{\varepsilon _{t}}{ \varepsilon _{t}^{*}},1\right) P_{t}, \\ \phi _{t}^{b}\left( \varepsilon _{t}\right)= & {} \max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}},1\right) . \end{aligned}$$

Substituting these equations into the previous definitions of \(Q_{t},\) \( p_{t}^{g},\) \(p_{t}^{l},\) and \(p_{t}^{b},\) we obtain their asset pricing equations as in the proposition. \(\square \)

Proof of Proposition 4:

In a frozen equilibrium, \(P_{t}=0\) for all t. No firms want to sell any good assets since the holding value \(p_{t}^{g}>0.\) In a frozen equilibrium, the market for long-term assets breaks down. We conjecture that the value function \(V_{t}\) takes the following form:

$$\begin{aligned} V_{t}\left( k_{t},\varepsilon _{t},h_{t}^{g},h_{t}^{l},b_{t}\right) =q_{t}(\varepsilon _{t})k_{t}+\phi _{t}^{g}(\varepsilon _{t})h_{t}^{g}+\phi _{t}^{l}(\varepsilon _{t})h_{t}^{l}+\phi _{t}^{b}(\varepsilon _{t})b_{t}. \end{aligned}$$

Then we can write

$$\begin{aligned} \beta E\left[ V_{t+1}\left( k_{t+1},\varepsilon _{t+1},h_{t+1}^{g},h_{t+1}^{l},b_{t+1}\right) \right] =Q_{t}k_{t+1}+p_{t}^{g}h_{t+1}^{g}+p_{t}^{l}h_{t+1}^{l}+p_{t}^{b}b_{t+1} , \end{aligned}$$

where we define \(Q_{t},\) \(p_{t}^{g},\) \(p_{t}^{l},\) and \(p_{t}^{b}\) as before. The Bellman equation is given by

$$\begin{aligned} V_{t}\left( k_{t},\varepsilon _{t},h_{t}^{g},h_{t}^{l},b_{t}\right) =\max _{i_{t}}\, C_{t}+\beta E\left[ V_{t+1}\left( k_{t+1},\varepsilon _{t+1},h_{t+1}^{g},h_{t+1}^{l},b_{t+1}\right) \right] \end{aligned}$$
(A.5)

subject to (5), \(b_{t+1}/R_{\textit{ft}}\ge -\mu _{t}k_{t},\) and

$$\begin{aligned} i_{t}=R_{kt}k_{t}+ch_{t}^{g}+b_{t}-\frac{b_{t+1}}{R_{\textit{ft}}}-C_{t}. \end{aligned}$$

Using the flow-of-funds constraint, we can compute the objective function in (A.5) as

$$\begin{aligned}&C_{t}+\beta E\left[ V_{t+1}\left( k_{t+1},\varepsilon _{t+1},h_{t+1}^{g},h_{t+1}^{l},b_{t+1}\right) \right] \\&\quad =R_{kt}k_{t}-i_{t}+ch_{t}^{g}+Q_{t}\left[ \left( 1-\delta \right) k_{t}+i_{t}\varepsilon _{t}\right] +p_{t}^{g}h_{t+1}^{g}+p_{t}^{l}h_{t+1}^{l} \\&\quad =\left[ R_{kt}+\left( 1-\delta \right) Q_{t}\right] k_{t}+\left( Q_{t}\varepsilon _{t}-1\right) i_{t}+\left( p_{t}^{g}+c\right) h_{t}^{g}+p_{t}^{l}h_{t}^{l}, \end{aligned}$$

where we have used the fact that \(h_{t+1}^{g}=h_{t}^{g}=h_{0}^{g}\) and \( h_{t}^{l}=h_{t}^{l}=h_{0}^{l}\) for all t. We then obtain the investment rule in the proposition. Substituting this investment rule back into (A.5) and matching coefficients, we obtain

$$\begin{aligned} q_{t}(\varepsilon _{t})= & {} \left( 1-\delta \right) Q_{t}+R_{kt}\left[ 1+\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}}-1,0\right) \right] +\max \left( \frac{\varepsilon _{t}}{\varepsilon _{t}^{*}}-1,0\right) \mu _{t}, \\ \phi _{t}^{g}(\varepsilon _{t})= & {} p_{t}^{g}+c\left[ 1+\max \left( \frac{ \varepsilon _{t}}{\varepsilon _{t}^{*}}-1,0\right) \right] , \\ \phi _{t}^{l}(\varepsilon _{t})= & {} p_{t}^{l},\, \\ \phi _{t}^{b}\left( \varepsilon _{t}\right)= & {} 1+\max \left( \frac{ \varepsilon _{t}}{\varepsilon _{t}^{*}}-1,0\right) . \end{aligned}$$

Using the definitions of \(Q_{t},p_{t}^{g},p_{t}^{l},\) and \(p_{t}^{b},\) we can derive (16), (17), and \(p_{t}^{l}=\beta E_{t}\left( p_{t+1}^{l}\right) .\) By the transversality condition, we deduce that \(p_{t}^{l}=0\) for all t. \(\square \)

Proof of Proposition 5:

By (36), \(Q_{t}P_{t}\varepsilon _{t}\le Q_{t}P_{t}\varepsilon _{\max }<p^{g}.\) No firms want to sell the good assets so that \(\varepsilon _{t}^{**}=\varepsilon _{\max }\) and \(\varTheta _{t}=0\). Thus \( P_{t}=p_{t}^{l}\) by (31). We then use (29) to derive (33) and use (30) to derive (32).

We use Proposition 3 to derive Eq. (44) for aggregate investment. We then obtain the law of motion for aggregate capital in Eq. (34). Using (3), (4), and the labor market-clearing condition \( N_{t}=1\), we can derive that

$$\begin{aligned} W_{t}=\left( 1-\alpha \right) A\left( \frac{K_{t}}{N_{t}}\right) ^{\alpha }=\left( 1-\alpha \right) AK_{t}^{\alpha },\, R_{kt}=\alpha A\left( \frac{N_{t}}{K_{t}}\right) ^{1-\alpha }=\alpha AK^{\alpha -1}. \end{aligned}$$

In addition,

$$\begin{aligned} Y_{t}=\int y_{\textit{jt}}\mathrm{d}j=\int Ak_{\textit{jt}}^{\alpha }n_{\textit{jt}}^{1-\alpha }\mathrm{d}j=AK^{\alpha }N^{1-\alpha }=AK^{\alpha }. \end{aligned}$$

By the decision rule in Proposition 3 and the market-clearing condition for financial assets,

$$\begin{aligned} \int x_{t}\mathrm{d}F\left( \varepsilon \right) =\int \left( s_{t}^{g}+s_{t}^{l}\right) \mathrm{d}F\left( \varepsilon \right) , \end{aligned}$$

we can derive

$$\begin{aligned} \int _{\varepsilon _{t}\le \varepsilon _{t}^{*}}x_{t}\mathrm{d}F\left( \varepsilon \right) =\pi +\left( 1-\pi \right) \left[ 1-F\left( \varepsilon _{t}^{**}\right) \right] . \end{aligned}$$

Since \(x_{t}\) is indeterminate at the individual firm level, we can set

$$\begin{aligned} x_{\textit{jt}}=\left\{ \begin{array}{c@{\quad }c} \frac{\pi +\left( 1-\pi \right) \left[ 1-F\left( \varepsilon _{t}^{**}\right) \right] }{F\left( \varepsilon _{t}^{*}\right) } &{} \text {if } \varepsilon _{\textit{jt}}<\varepsilon _{t}^{**}\, \\ 0 &{} \text {otherwise} \end{array} \right. , \end{aligned}$$

for all j. \(\square \)

Proof of Proposition 6:

By Lemma 1, there exists a unique cutoff value \(\varepsilon _{b}^{*}\in \left( \varepsilon _{\min },\varepsilon _{\max }\right) \) to Eq. (24). In the bubbly lemon steady state, \(P>0\) and hence Eq. (32) is equivalent to Eq. (24). This implies that \(\varepsilon _{b}^{*}\) is the investment threshold in the bubbly lemon steady state. By (24) and (33), we can derive \(p^{g}\) as in (40). Using Eqs. (16) and (22), we can show that the steady-state capital stock is equal to \(K\left( \varepsilon _{b}^{*}\right) \) where \(K\left( \cdot \right) \) is given in (27). Using Eqs. (22) and (34), we can solve for P as in (41). We need to verify that the condition

$$\begin{aligned} 0<P<\frac{\varepsilon _{b}^{*}}{\varepsilon _{\max }}p^{g} \end{aligned}$$

holds in the steady state. But this is equivalent to (39). \(\square \)

Proof of Proposition 7:

In a pooling equilibrium the restriction in (45) must hold. Firms with \(\varepsilon _{\textit{jt}}\ge \varepsilon _{t}^{**}\) sell their good assets. By Proposition 3 and the market-clearing conditions for assets, we can compute \(\varTheta _{t}\) as in the proposition. Using the decision rule for investment in Proposition 3 and aggregating individual decision rules, we obtain (43) and (44). \(\square \)

Proof of Lemma 2:

Under Assumption 1, Lemma 1 establishes the existence of a unique solution \(\varepsilon _{b}^{*}\) to Eq. (24). Since \(\beta \left( 1+\int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\left( \frac{\varepsilon }{\varepsilon ^{*}}-1\right) \mathrm{d}F\left( \varepsilon \right) \right) \) decreases with \(\varepsilon ^{*},\) it follows that

$$\begin{aligned} \beta \left( 1+\int _{\varepsilon ^{**}}^{\varepsilon _{\max }}\left( \frac{\varepsilon }{\varepsilon ^{**}}-1\right) \mathrm{d}F\left( \varepsilon \right) \right) <\beta \left( 1+\int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\left( \frac{\varepsilon }{\varepsilon ^{*}}-1\right) \mathrm{d}F\left( \varepsilon \right) \right) =1 \end{aligned}$$

for \(\varepsilon ^{**}>\varepsilon _{b}^{*}.\) Thus we deuce that

$$\begin{aligned} \underset{\varepsilon ^{*}\uparrow \varepsilon ^{**}}{\lim } \varTheta \left( \varepsilon ^{**}\right) \left( \frac{\varepsilon ^{**}}{\varepsilon ^{*}}\right) +(1-\varTheta \left( \varepsilon ^{**}\right) )\beta \left( 1+\int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\left( \frac{\varepsilon }{\varepsilon ^{*}} -1\right) \mathrm{d}F\left( \varepsilon \right) \right)< & {} 1 \\ \underset{\varepsilon ^{*}\downarrow \varepsilon _{b}^{*}}{\lim } \varTheta \left( \varepsilon ^{**}\right) \left( \frac{\varepsilon ^{**}}{\varepsilon ^{*}}\right) +(1-\varTheta \left( \varepsilon ^{**}\right) )\beta \left( 1+\int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\left( \frac{\varepsilon }{\varepsilon ^{*}} -1\right) \mathrm{d}F\left( \varepsilon \right) \right)> & {} 1. \end{aligned}$$

Since the expression on the right-hand side of Eq. (50) decreases continuously with \(\varepsilon ^{*}, \) it follows from the intermediate value theorem that there exists a unique solution to \(\varepsilon ^{*}\) in \(\left( \varepsilon _{b}^{*},\varepsilon ^{**}\right) \) in Eq. (50). \(\square \)

Proof of Proposition 8:

Following the strategy used in the context, we know pooling equilibrium can be supported if and only if

$$\begin{aligned} 0<c<\overline{c}^{P}\left( \pi \right) , \end{aligned}$$

where \(\overline{c}^{P}\left( \pi \right) =\underset{\varepsilon ^{**}\in \left[ \varepsilon _{b}^{*},\varepsilon _{\max }\right] }{\max } \varGamma \left( \varepsilon ^{**},\pi \right) \), and

$$\begin{aligned} \varGamma \left( \varepsilon ^{**},\pi \right) \equiv \frac{\frac{ \delta K\left( \varPhi \left( \varepsilon ^{**}\right) \right) }{ \int _{\varPhi \left( \varepsilon ^{**}\right) }^{\varepsilon _{\max }}\varepsilon \mathrm{d}F\left( \varepsilon \right) }-\alpha AK\left( \varPhi \left( \varepsilon ^{**}\right) \right) ^{\alpha }-\mu K\left( \varPhi \left( \varepsilon ^{**}\right) \right) }{\left( 1-\pi \right) +\frac{\varPhi \left( \varepsilon ^{**}\right) }{\varepsilon ^{**}}\left[ \pi +\left( 1-\pi \right) \frac{\int _{\varepsilon ^{**}}^{\varepsilon _{\max }}\varepsilon \mathrm{d}F\left( \varepsilon \right) }{ \int _{\varPhi \left( \varepsilon ^{**}\right) }^{\varepsilon _{\max }}\varepsilon \mathrm{d}F\left( \varepsilon \right) }\right] \left[ \frac{\beta \left( 1+\int _{\varPhi \left( \varepsilon ^{**}\right) }^{\varepsilon _{\max }}\left( \frac{\varepsilon }{\varPhi \left( \varepsilon ^{**}\right) }-1\right) \mathrm{d}F\left( \varepsilon \right) \right) }{1-\beta \left( 1+\int _{\varepsilon ^{**}}^{\varepsilon _{\max }}\left( \frac{ \varepsilon }{\varepsilon ^{**}}-1\right) \mathrm{d}F\left( \varepsilon \right) \right) }\right] } \end{aligned}$$

As in the proof of Proposition 2 and Lemma 3, for a sufficiently small \(\mu , \) the expression

$$\begin{aligned} \frac{\delta K\left( \varepsilon ^{*}\right) }{\int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\varepsilon \mathrm{d}F\left( \varepsilon \right) }-\alpha A \left[ K\left( \varepsilon ^{*}\right) \right] ^{\alpha }-\mu K\left( \varepsilon ^{*}\right) \end{aligned}$$

increases with \(\varepsilon ^{*}.\) Thus the numerator of the expression for \(\varGamma \) given above satisfies

$$\begin{aligned}&\frac{\delta K\left( \varepsilon ^{*}\right) }{\int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\varepsilon \mathrm{d}F\left( \varepsilon \right) } -\alpha AK\left( \varepsilon ^{*}\right) ^{\alpha }-\mu K\left( \varepsilon ^{*}\right) \\&\quad \ge \frac{\delta K\left( \varepsilon _{b}^{*}\right) }{ \int _{\varepsilon _{b}^{*}}^{\varepsilon _{\max }}\varepsilon \mathrm{d}F\left( \varepsilon \right) }-\alpha AK\left( \varepsilon _{b}^{*}\right) ^{\alpha }-\mu K\left( \varepsilon _{b}^{*}\right) =c_{H}>0 \end{aligned}$$

for any \(\varepsilon ^{*}\ge \varepsilon _{b}^{*}.\) In addition, it follows from Lemma 1 that

$$\begin{aligned} 1-\beta \left( 1+\int _{\varepsilon ^{**}}^{\varepsilon _{\max }}\left( \frac{\varepsilon }{\varepsilon ^{**}}-1\right) \mathrm{d}F\left( \varepsilon \right) \right) >0 \end{aligned}$$

for \(\varepsilon ^{**}>\varepsilon _{b}^{*}\) so that the denominator of the expression for \(\varGamma \) given above is also positive. We deduce that

$$\begin{aligned} \varGamma \left( \pi ,\varepsilon ^{**}\right) \ge 0 \end{aligned}$$

for all \(\varepsilon ^{**}\in \left( \varepsilon _{b}^{*},\varepsilon _{\max }\right) .\) Since

$$\begin{aligned} \lim _{\varepsilon ^{**}\downarrow \varepsilon _{b}^{*}}\beta \left( 1+\int _{\varepsilon ^{**}}^{\varepsilon _{\max }}\left( \frac{ \varepsilon }{\varepsilon ^{**}}-1\right) \mathrm{d}F\left( \varepsilon \right) \right) =1 \end{aligned}$$

and other limits are finite, we have

$$\begin{aligned} \lim _{\varepsilon ^{**}\downarrow \varepsilon _{b}^{*}}\varGamma \left( \pi ,\varepsilon ^{**}\right) =0. \end{aligned}$$

By the intermediate value theorem, there exists a solution to \(\varepsilon ^{**}\) in \(\left( \varepsilon _{b}^{*},\varepsilon _{\max }\right) \) in Eq. (52).

We can verify that

$$\begin{aligned} \varGamma \left( \varepsilon _{\max }\right) =\frac{c_{H}c_{L}}{\pi c_{H}+\left( 1-\pi \right) c_{L}}=\underline{c}^{B}\left( \pi \right) , \end{aligned}$$

where the first equality uses the fact that \(\varPhi \left( \varepsilon _{\max }\right) =\varepsilon _{b}^{*}\) and the second uses the definition of \( \underline{c}^{B}\left( \pi \right) \) by Eq. (38). Therefore we know that \(\overline{c}^{p}\left( \pi \right) >\underline{c}^{B}\left( \pi \right) \).

The steady-state capital stock \(K\left( \varepsilon _{p}^{*}\right) \) is derived from Eq. (16) using \(\varepsilon _{p}^{*}=1/Q. \) \(\square \)

Proof of Proposition 9:

We apply Proposition 4. Aggregation leads to the equations for aggregate capital and investment in the proposition. \(\square \)

Proof of Proposition 10:

By Eq. (16), we can derive the steady-state capital stock \(K\left( \varepsilon ^{*}\right) \) defined in (27). We need to solve for \(\varepsilon ^{*}.\) By (22) and (56), we can derive Eq. (58). As in the proof of Proposition 8, we know that the right-hand side of (58) strictly increases with \(\varepsilon ^{*}\). In addition, we can show that

$$\begin{aligned} \underset{\varepsilon ^{**}\uparrow \varepsilon _{\max }}{\lim } \frac{\delta K\left( \varepsilon ^{*}\right) }{\int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\varepsilon \mathrm{d}F\left( \varepsilon \right) }-\alpha AK\left( \varepsilon ^{*}\right) ^{\alpha }-\mu K\left( \varepsilon ^{*}\right) =+\infty \end{aligned}$$

and

$$\begin{aligned}&\underset{\varepsilon ^{*}\downarrow \varepsilon _{\min }}{\lim }\frac{ \delta K\left( \varepsilon ^{*}\right) }{\int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\varepsilon \mathrm{d}F\left( \varepsilon \right) }-\alpha AK\left( \varepsilon ^{*}\right) ^{\alpha }-\mu K\left( \varepsilon ^{*}\right) \\&\quad =K\left( \varepsilon _{\min }\right) \left[ \frac{\delta }{ \int _{\varepsilon _{\min }}^{\varepsilon _{\max }}\varepsilon \mathrm{d}F\left( \varepsilon \right) }-\frac{1/\beta -1+\delta }{\int _{\varepsilon _{\min }}^{\varepsilon _{\max }}\varepsilon \mathrm{d}F\left( \varepsilon \right) }\right] =K\left( \varepsilon _{\min }\right) \frac{1-1/\beta }{\int _{\varepsilon _{\min }}^{\varepsilon _{\max }}\varepsilon \mathrm{d}F\left( \varepsilon \right) }<0. \end{aligned}$$

Therefore there exists a unique solution \(\varepsilon ^{*}\in \left( \varepsilon _{\min },\varepsilon _{\max }\right) \) to Eq. (58) for any \(c>0\).

Proof of Proposition 11:

By Lemma 3, for a sufficiently small \(\mu \), \(K\left( \varepsilon ^{*}\right) \) increases with \(\varepsilon ^{*}\). To prove \(K\left( \varepsilon _{p}^{*}\right)>K\left( \varepsilon _{b}^{*}\right) >K\left( \varepsilon _{a}^{*}\right) \), we only need to show that \( \varepsilon _{p}^{*}>\varepsilon _{b}^{*}>\varepsilon _{a}^{*}\) when \(\mu \) is small enough. By Lemma 2 and Proposition 8, \(\varepsilon _{p}^{*}>\varepsilon _{b}^{*}.\)

By definition,

$$\begin{aligned} D\left( \varepsilon ^{*}\right) \equiv \frac{\delta K\left( \varepsilon ^{*}\right) }{\int _{\varepsilon ^{*}}^{\varepsilon _{\max }}\varepsilon \mathrm{d}F\left( \varepsilon \right) }-\left[ \alpha AK\left( \varepsilon ^{*}\right) ^{\alpha }-\mu K\left( \varepsilon ^{*}\right) +\left( 1-\pi \right) c\right] . \end{aligned}$$

By (37) and (38), \(\varepsilon _{b}^{*}\) satisfies the equation

$$\begin{aligned} D\left( \varepsilon _{b}^{*}\right) =\left( 1-\pi \right) \left( \bar{c} ^{B}\left( \pi \right) -c\right) . \end{aligned}$$
(A.6)

By Proposition 10, \(\varepsilon _{a}^{*}\) satisfies

$$\begin{aligned} D\left( \varepsilon _{a}^{*}\right) =0. \end{aligned}$$
(A.7)

As shown in Proposition 6, a bubbly lemon steady-state equilibrium can be supported if \(c<\bar{c}^{B}\left( \pi \right) \). Therefore Eqs. (A.6) and (A.7) jointly imply

$$\begin{aligned} D\left( \varepsilon _{b}^{*}\right) >D\left( \varepsilon _{a}^{*}\right) . \end{aligned}$$
(A.8)

As in the proof of Proposition 2, \(D\left( \varepsilon ^{*}\right) \) strictly increases with \(\varepsilon ^{*}\) for a sufficiently small \(\mu \). Then Eq. (A.8) implies that \(\varepsilon _{b}^{*}>\varepsilon _{a}^{*}.\) \(\square \)

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Dong, F., Miao, J. & Wang, P. The perils of credit booms. Econ Theory 66, 819–861 (2018). https://doi.org/10.1007/s00199-017-1076-6

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