21. Banking

Note

本章主题:银行的实证。 §21.1 冲击向实体经济的传导Paravisini (2008) 用阿根廷 MYPES 项目作工具(构造外生预期融资 \(\hat C_{iw}\))2SLS (21.1)–(21.3),银行每收 1 USD 项目资金放贷 0.66 USD;Khwaja-Mian (2008) 用巴基斯坦 1998 核试验冻结美元存款的流动性冲击,分银行借贷渠道(公司层固定效应 (21.4) 解决偏误)与公司借贷渠道((21.5) OLS 给下界),大公司受冲击更小;Chodorow-Reich (2014) 用银企关系黏性 + 雷曼/ABX 工具 (21.6) 估银行健康对就业的影响(信贷供给↑→就业↑,对无债市渠道的中小企业尤强)。§21.2 货币政策与银行渠道Jimenez et al. (2012) 西班牙信贷登记,紧缩货币政策→收紧放贷 (21.7),高资本/流动性银行受影响小(假设 1、2);Jimenez et al. (2014) 聚焦贷款风险 (21.8)–(21.9):紧缩→贷给更安全公司,自有资本高者反更冒险;Ioannidou et al. (2015) 玻利维亚:宽松→更差贷款质量(事后违约更高);Drechsler et al. (2017) 存款渠道:银行有市场势力→存款利率对货币政策不敏感(存款利差随市场势力 \(\mathcal M\) 与联邦基金利率 \(f\) 增)→紧缩时存款外流→银行缩贷(实体受损)。§21.3 银行与信息Schenone (2010) 关系借贷强度 (21.10),IPO 前利差对强度呈「U」形(信息溢出 vs 信息处理),IPO 后单调下降(信息不对称消失);Giannetti et al. (2017):银行在公共信贷登记信息共享改革前下调好借款人、上调坏借款人评级以保信息租/避债权人挤兑 (21.11)–(21.13)(阿根廷自然实验)。

Note

Chapter theme: the empirics of banking. §21.1 Transmission of shocks to the real economy: Paravisini (2008) uses Argentina's MYPES program as an instrument (constructing exogenous expected financing \(\hat C_{iw}\)) in a 2SLS (21.1)–(21.3), with banks lending 0.66 USD per 1 USD of program funds; Khwaja-Mian (2008) use the liquidity shock from Pakistan's 1998 nuclear-test dollar-deposit freeze, separating the bank lending channel (firm FE (21.4) fixes the bias) and the firm borrowing channel ((21.5) OLS gives a lower bound), with large firms suffering less; Chodorow-Reich (2014) uses bank-firm relationship stickiness + Lehman/ABX instruments (21.6) to estimate bank health's effect on employment (credit supply↑→employment↑, especially for SMEs without bond access). §21.2 Monetary policy and banking channels: Jimenez et al. (2012) Spanish credit registry, tight policy → tighter lending (21.7), high-capital/liquidity banks less affected (Hypotheses 1, 2); Jimenez et al. (2014) focus on loan risk (21.8)–(21.9): tightening → lending to safer firms, well-capitalized banks taking more risk; Ioannidou et al. (2015) Bolivia: loosening → worse loan quality (higher ex-post default); Drechsler et al. (2017) deposit channel: banks have market power → deposit rates insensitive to policy (the deposit spread rises in market power \(\mathcal M\) and the Fed funds rate \(f\)) → contraction causes deposit outflow → banks cut loans (hurting the real economy). §21.3 Banking and information: Schenone (2010) relationship-lending intensity (21.10), pre-IPO the spread is "U"-shaped in intensity (information spillover vs processing), post-IPO monotonically declining (asymmetry disappears); Giannetti et al. (2017): before a public-credit-registry information-sharing reform, banks downgrade good borrowers and upgrade bad ones to protect information rent / avoid creditor runs (21.11)–(21.13) (an Argentina natural experiment).

21.1 Transmission of Shocks to Banks to the Real Economy

21.1.1 银行外部融资摩擦对其放贷的影响:Paravisini (2008). 用阿根廷数据研究银行放贷对外部融资的敏感性。MYPES(1993–1999 中小企业信贷项目,美洲开发银行资助,以平均存款利率给 3 年融资,要求银行每收 0.75 USD 项目资金须向合资格借款人放贷 1 USD)的强度(波次)变异被利用。基本回归:

$$\ln L_{it}-\ln L_{i,t-1}=\alpha_i+\alpha_t+\beta_0(\ln F_{it}-\ln F_{i,t-1})+\boldsymbol\gamma'\mathbf X_{it}+\varepsilon_{it} \tag{21.1}$$

\(F_{it}\) 为净监管准备金的全部资金来源、\(L_{it}\) 放贷、\(\alpha_i/\alpha_t\) 银行/时间 FE。内生性:\(\ln F\) 与经济条件相关(更好条件→更高存款与贷款)→ 用 2SLS。工具:MYPES 实际额 \(C_{iw}\) 因银行自选择而内生,故构造外生预期 MYPES 融资——先用 probit 估全部银行(含未参与者)参与波次 \(w\) 的概率 \(\hat p_{iw}\),再构造

$$\hat C_{iw}=A_w\left[\frac12\frac{\hat p_{iw}Zregion_i}{\sum_{j=1}^{n_w}\hat p_{iw}Zregion_j}+\frac12\frac{\hat p_{iw}Zsize_i}{\sum_{j=1}^{n_w}\hat p_{iw}Zsize_j}\right]$$

(\(A_w\) 波次总融资、\(Zregion/Zsize\) 行政分配公式给贫省/小贷款规模银行更高比例)。2SLS:第一阶段 \(\ln F_{it}-\ln F_{i,t-1}=\phi_i+\phi_t+\delta_0(\ln\hat C_{it}-\ln\hat C_{i,t-1})+\boldsymbol\Gamma'\mathbf X_{it}+e_{it}\) (21.2),第二阶段以拟合值代入 (21.1) 得 (21.3) 的真 \(\beta_0\)。结果:第一阶段每收 1 USD 预期 MYPES 银行资源增 1 USD(无替代、MYPES 边际内、银行仍缺资本);第二阶段每收 1 USD 放贷 0.66 USD(其余为重标旧债为项目债)。

21.1.1 Bank's external financing friction and its lending: Paravisini (2008). Uses Argentina data to study the sensitivity of bank lending to external financing. The intensity (waves) of MYPES (a 1993–1999 SME credit program funded by the Inter-American Development Bank, giving 3-year financing at the average deposit rate, requiring banks to lend 1 USD per 0.75 USD of program funds) is exploited. The basic regression:

$$\ln L_{it}-\ln L_{i,t-1}=\alpha_i+\alpha_t+\beta_0(\ln F_{it}-\ln F_{i,t-1})+\boldsymbol\gamma'\mathbf X_{it}+\varepsilon_{it} \tag{21.1}$$

\(F_{it}\) all funding net of regulatory reserves, \(L_{it}\) loans, \(\alpha_i/\alpha_t\) bank/time FE. Endogeneity: \(\ln F\) correlates with economic conditions (better conditions → more deposits and loans) → use 2SLS. Instrument: actual MYPES \(C_{iw}\) is endogenous (bank self-selection), so construct an exogenous expected MYPES — first estimate by probit the participation probability \(\hat p_{iw}\) of all banks (including non-participants) in wave \(w\), then

$$\hat C_{iw}=A_w\left[\frac12\frac{\hat p_{iw}Zregion_i}{\sum_{j=1}^{n_w}\hat p_{iw}Zregion_j}+\frac12\frac{\hat p_{iw}Zsize_i}{\sum_{j=1}^{n_w}\hat p_{iw}Zsize_j}\right]$$

(\(A_w\) total wave funding; the administrative formula gives poorer provinces \(Zregion\) / smaller-loan banks \(Zsize\) higher fractions). 2SLS: first stage \(\ln F_{it}-\ln F_{i,t-1}=\phi_i+\phi_t+\delta_0(\ln\hat C_{it}-\ln\hat C_{i,t-1})+\boldsymbol\Gamma'\mathbf X_{it}+e_{it}\) (21.2), second stage plugging fitted values into (21.1) for the true \(\beta_0\) (21.3). Results: the first stage implies bank resources rise 1 USD per 1 USD of expected MYPES (no substitution, MYPES infra-marginal, banks still need capital); the second stage implies banks lend 0.66 USD per 1 USD (relabeling previous debt as program debt).

21.1.2 Bank Liquidity on Firms: Khwaja and Mian (2008) — and 21.1.3 Chodorow-Reich (2014)

21.1.2 Khwaja-Mian (2008). 用巴基斯坦 1998 核试验数据:核试后政府冻结全部美元存款、仅以不利汇率允许提取卢比,美元存款者恐慌挤兑→重依美元存款的银行流动性问题更重(图 21.1、21.2)。两问:1. 银行能否易筹资?2. 若不能,公司能否抵消放贷减少?银行借贷渠道(答 1):\(\Delta L_{ij}=\beta_0+\beta_1\Delta D_i+\eta_j+\varepsilon_{ij}\) (21.4)(\(\Delta L_{ij}\) 银行 \(i\) 对公司 \(j\) 贷款变化=集约边际、\(\Delta D_i\) 活期存款变化、\(\eta_j\) 公司 FE)。OLS 因 \(\text{Cov}(\Delta D_i,\eta_j)>0\)(差经济→更少存款且更少贷款需求)使 \(\beta_0^{OLS}>\beta_1\),故需公司 FE(无偏,但只剩多银行借款公司=子样本)。公司借贷渠道(答 2):跨银行聚合得 \(\Delta\bar D_j\),\(\Delta Y_j=\beta_0^{Firm}+\beta_1^{Firm}\Delta\bar D_j+\eta_j\) (21.5);\(\text{Cov}(\Delta\bar D_j,\eta_j)<0\)(新兴市场大银行更暴露美元存款、更盈利公司向大银行借→高 \(\Delta\bar D_j\) 关联高盈利公司,更不易被削贷),故 OLS 的 \(\beta_1^{Firm,OLS}\) 是真值的下界结果:集约边际(图 21.3)流动性低→贷款更小;广延边际(图 21.4)→退出概率更高、进入更低;公司借贷渠道(图 21.5)大公司受冲击更小。

21.1.3 Chodorow-Reich (2014). 用公司层机密就业数据(BLS)+ Dealscan 银企关系数据研究放贷摩擦对就业的影响。方法依赖两假设:银企关系黏性(图 21.6:上次牵头行有 67% 概率为下次牵头行);2008 危机源于公司贷款部门之外。构造公司 \(i\) 的信贷可得变化

$$\Delta\hat L_{i,s}=\sum_{b\in s}\alpha_{b,i,last}\Delta L_{-i,b} \tag{21.6}$$

(\(\alpha_{b,i,last}\) 银行 \(b\) 在 \(i\) 上次危机前贷款银团的份额、\(\Delta L_{-i,b}=\frac{\sum_{j\ne i}\alpha_{b,j,crisis}L_{b,j,crisis}}{0.5\sum_{j\ne i}\alpha_{b,j,normal}L_{b,j,normal}}\),0.5 因正常期 18 月是危机期 9 月两倍)。用四组工具消除 \(\Delta L_b\) 内生性:1. 雷曼共银团暴露;2. ABX(有毒 MBS)暴露;3. 银行报表项;4. 三者组合(图 21.7)。结果:信贷供给↑→获贷概率↑(图 21.8)、利差↓(图 21.9)、就业增长↑(图 21.10);对无债市渠道的中小企业尤强(图 21.11)。聚合分析受批评(Dealscan 公司非全样本代表)。

21.1.2 Khwaja-Mian (2008). Uses Pakistan's 1998 nuclear-test data: after the tests the government froze all dollar deposits, allowing withdrawal only in rupees at an unfavorable rate; USD depositors ran banks → banks relying more on USD deposits had worse liquidity problems (Figures 21.1, 21.2). Two questions: 1. Can banks easily raise financing? 2. If not, can firms offset the lending reduction? Bank lending channel (answers 1): \(\Delta L_{ij}=\beta_0+\beta_1\Delta D_i+\eta_j+\varepsilon_{ij}\) (21.4) (\(\Delta L_{ij}\) = bank \(i\)'s loan change to firm \(j\) = intensive margin, \(\Delta D_i\) demand-deposit change, \(\eta_j\) firm FE). OLS, with \(\text{Cov}(\Delta D_i,\eta_j)>0\) (worse economy → less deposit and less loan demand), gives \(\beta_0^{OLS}>\beta_1\), so we need firm FE (unbiased, but only multi-bank firms remain = sub-sample). Firm borrowing channel (answers 2): aggregating across banks gives \(\Delta\bar D_j\), \(\Delta Y_j=\beta_0^{Firm}+\beta_1^{Firm}\Delta\bar D_j+\eta_j\) (21.5); \(\text{Cov}(\Delta\bar D_j,\eta_j)<0\) (in emerging markets big banks have more USD exposure, more profitable firms borrow from big banks → high \(\Delta\bar D_j\) associates with profitable firms less likely to be cut), so OLS's \(\beta_1^{Firm,OLS}\) is a lower bound on the truth. Results: intensive margin (Figure 21.3) lower liquidity → smaller loans; extensive margin (Figure 21.4) → higher exit, lower entry probability; firm borrowing channel (Figure 21.5) large firms suffer less.

21.1.3 Chodorow-Reich (2014). Uses firm-level confidential employment data (BLS) + Dealscan bank-firm data to study lending frictions' effect on employment. Relies on two assumptions: bank-firm relationships are sticky (Figure 21.6: a previous lead bank has a 67% probability of being the next lead); the 2008 crisis originated outside the corporate loan sector. Construct firm \(i\)'s credit-availability change

$$\Delta\hat L_{i,s}=\sum_{b\in s}\alpha_{b,i,last}\Delta L_{-i,b} \tag{21.6}$$

(\(\alpha_{b,i,last}\) bank \(b\)'s share of \(i\)'s last pre-crisis loan syndicate, \(\Delta L_{-i,b}=\frac{\sum_{j\ne i}\alpha_{b,j,crisis}L_{b,j,crisis}}{0.5\sum_{j\ne i}\alpha_{b,j,normal}L_{b,j,normal}}\), the 0.5 because the normal period (18 months) is twice the crisis period (9 months)). Four instrument groups remove \(\Delta L_b\)'s endogeneity: 1. Lehman cosyndication exposure; 2. ABX (toxic MBS) exposure; 3. bank statement items; 4. their combination (Figure 21.7). Results: credit supply↑ → higher loan probability (Figure 21.8), lower spread (Figure 21.9), higher employment growth (Figure 21.10); especially strong for SMEs without bond access (Figure 21.11). The aggregate analysis is criticized (Dealscan firms are not representative of the whole sample).

21.2 Monetary Policy and Banking Channels (Jimenez et al.; Ioannidou et al.)

21.2.1 Jimenez et al. (2012) 货币政策对放贷的数量效应:西班牙(对欧央行政策影响小→近外生),用信贷登记 CIR 与公司 FE 比较同一公司在不同银行的放贷决定。主回归

$$\text{Loan Granted}_{ibt}=\beta_I\Delta IR_t+\beta_G\Delta GDP_t+\beta_{IC}(\Delta IR_t\times\Delta CAP_{b,t-1})+\beta_{IL}(\Delta IR_t\times\Delta LIQ_{b,t-1})+\beta_{GC}(\Delta GDP_t\times\Delta CAP)+\beta_{GL}(\Delta GDP_t\times\Delta LIQ)+\cdots \tag{21.7}$$

(\(\Delta IR\) 短期利率变化、\(\Delta CAP/\Delta LIQ\) 银行资本/流动性比率)。假设 1:\(\beta_I<0\)(紧缩→收紧放贷)、\(\beta_G>0\)。假设 2:\(\beta_{IC},\beta_{IL}>0\)(高资本/流动性银行抑制 \(\beta_I<0\))、\(\beta_{GC},\beta_{GL}<0\)。结果(图 21.12):支持两假设(仅 \(\beta_{GL}<0\) 不显著)。

21.2.2 Jimenez et al. (2014) 货币政策对放贷的风险偏好效应(同数据,聚焦贷款风险):

$$\text{Loan Granted}_{ibt}=\alpha_t+\alpha_i+\alpha_b+\beta\mathbf 1\{Firm\ Risk_{it}\}+\delta(\Delta\text{Overnight Rate}_{t-1}\times\mathbf 1\{Firm\ Risk\})+\gamma(\Delta\text{Overnight Rate}\times\mathbf 1\{Firm\ Risk\}\times\ln(\text{Bank Capital}_{b,t-1}))+\cdots \tag{21.8}$$

及对贷款额取对数的 (21.9)。\(\mathbf 1\{Firm\ Risk\}\) =1 若公司前 4 年有不良贷款。结果(图 21.13):\(\delta,\delta'\) 显著负(紧缩→贷给更安全公司、广延+集约边际);\(\gamma,\gamma'\) 显著正(自有资本高的银行在紧缩期反更冒险)。

21.2.3 Ioannidou et al. (2015) 宽松货币政策导致更差贷款质量:玻利维亚(peso 钉 USD、开放账户→货币政策外生,90% 存款 USD),聚焦事后贷款表现。主发现:短期利率低(宽松)→ 发放更高风险贷款(事后信用史更差、事前评级更低、事后表现更弱即违约率更高);对从多家银行借款的小公司效应更强。

21.2.1 Jimenez et al. (2012) the quantity effect of monetary policy on lending: Spain (small influence on ECB policy → nearly exogenous), using credit registry CIR and firm FE to compare lending decisions of different banks to the same firm. Main regression

$$\text{Loan Granted}_{ibt}=\beta_I\Delta IR_t+\beta_G\Delta GDP_t+\beta_{IC}(\Delta IR_t\times\Delta CAP_{b,t-1})+\beta_{IL}(\Delta IR_t\times\Delta LIQ_{b,t-1})+\beta_{GC}(\Delta GDP_t\times\Delta CAP)+\beta_{GL}(\Delta GDP_t\times\Delta LIQ)+\cdots \tag{21.7}$$

(\(\Delta IR\) short-rate change, \(\Delta CAP/\Delta LIQ\) bank capital/liquidity ratios). Hypothesis 1: \(\beta_I<0\) (tightening → tighter lending), \(\beta_G>0\). Hypothesis 2: \(\beta_{IC},\beta_{IL}>0\) (high-capital/liquidity banks dampen \(\beta_I<0\)), \(\beta_{GC},\beta_{GL}<0\). Results (Figure 21.12): both hypotheses supported (only \(\beta_{GL}<0\) not significant).

21.2.2 Jimenez et al. (2014) the risk-appetite effect of monetary policy (same data, focusing on loan risk):

$$\text{Loan Granted}_{ibt}=\alpha_t+\alpha_i+\alpha_b+\beta\mathbf 1\{Firm\ Risk_{it}\}+\delta(\Delta\text{Overnight Rate}_{t-1}\times\mathbf 1\{Firm\ Risk\})+\gamma(\Delta\text{Overnight Rate}\times\mathbf 1\{Firm\ Risk\}\times\ln(\text{Bank Capital}_{b,t-1}))+\cdots \tag{21.8}$$

and a log-loan-amount version (21.9). \(\mathbf 1\{Firm\ Risk\}=1\) if the firm had non-performing loans in the prior 4 years. Results (Figure 21.13): \(\delta,\delta'\) significantly negative (tightening → lending to safer firms, both extensive and intensive margins); \(\gamma,\gamma'\) significantly positive (well-capitalized banks take more risk in tight periods).

21.2.3 Ioannidou et al. (2015) looser policy → worse loan quality: Bolivia (peso pegged to USD, open account → exogenous policy, 90% deposits in USD), focusing on ex-post loan performance. Main finding: a lower short rate (loosening) → granting riskier loans (worse ex-ante credit history, lower ex-ante ratings, weaker ex-post performance, i.e. higher default); effects stronger for small firms borrowing from multiple banks.

21.2.4 Deposit Channel of Monetary Policy: Drechsler et al. (2017)

用 FDIC 存款量(1994–2014)+ Ratewatch 存款利率(1997–2014)数据。核心思想:银行有市场势力→存款利率对货币政策不敏感(图 21.14);货币紧缩(短期利率升)→存款变得不利→存款流出银行体系(图 21.15);银行以缩贷应对(如传统垄断利润最大化)——此即货币政策的存款渠道

模型:一期、无风险。代表家庭最大化 \(u(W_0)=\max\left(W^{\frac{\varepsilon-1}\varepsilon}+\lambda^{\frac1\varepsilon}\ell^{\frac{\varepsilon-1}\varepsilon}\right)^{\frac\varepsilon{\varepsilon-1}}\)(\(\lambda\) 份额、\(\varepsilon\) 财富与流动性服务 \(\ell\) 的替代弹性)。银行 \(i\) 在 \(t\) 的存款利差 \(s_{it}=f_t-r_{it}^{dep}\)(\(f_t\) 联邦基金率、\(r^{dep}\) 存款利率)。命题:设 \(\rho<1<\varepsilon,\eta\)(\(\eta\) 跨银行替代弹性),\(\mathcal M=1-(\eta-1)(N-1)\) 度量银行对存款的市场势力,\(\lambda\to0\) 时若 \(\mathcal M<\rho\) 利差为零,否则

$$s=\delta^{\frac1{\varepsilon-1}}\left(\frac{\mathcal M-\rho}{\varepsilon-\mathcal M}\right)^{\frac1{\varepsilon-1}}f$$

存款利差 \(s\) 随市场势力 \(\mathcal M\) 增、随联邦基金率 \(f\) 增、且 \(\mathcal M\) 越高随 \(f\) 增得越多。

实证:(1) 时序回归 \(\Delta y_{it}=\alpha_i+\beta_i\Delta f_t+\xi_{it}\) 按县 Herfindahl 分位(图 21.16:市场势力越高存款利率越不敏感=利差越敏感);(2) 行内回归 \(\Delta y_{ijct}=\alpha_i+\delta_{jt}+\zeta_c+\lambda_{st}+\gamma\Delta f_t\times HHI_c+\varepsilon_{ijct}\)(加银行-时间 FE \(\delta_{jt}\) 使 \(HHI_c\) 外生:多分行银行可在分行间调资满足需求,排除需求因素;图 21.17、21.18 紧缩→更高利差与存款外流);(3) 县级 \(y_{ct}=\alpha_c+\delta_t+\beta HHI_{c,t-1}+\gamma\Delta f_t\times HHI_{c,t-1}+\varepsilon_{ct}\)(图 21.19 紧缩→更少新贷、更慢就业/工资增长);(4) 银行级 \(\Delta y_{it}=\alpha_i+\delta_t+\beta HHI_{i,t-1}+\gamma\Delta f_t\times HHI_{i,t-1}+\varepsilon_{it}\)(图 21.20 紧缩→更少存款、更高批发融资、更小资产、更少地产贷)。一个有趣问题:紧缩期存款外流去哪了?(与影子银行相关。)

Uses FDIC deposit quantities (1994–2014) + Ratewatch deposit rates (1997–2014). Core idea: banks have market power → deposit rates are insensitive to policy (Figure 21.14); monetary contraction (short rate up) → deposits become unfavorable → deposits flow out of the banking system (Figure 21.15); banks respond by cutting loans (a traditional monopoly profit-maximization result) — this is the deposit channel of monetary policy.

Model: one period, no risk. The representative household maximizes \(u(W_0)=\max\left(W^{\frac{\varepsilon-1}\varepsilon}+\lambda^{\frac1\varepsilon}\ell^{\frac{\varepsilon-1}\varepsilon}\right)^{\frac\varepsilon{\varepsilon-1}}\) (\(\lambda\) a share, \(\varepsilon\) the elasticity of substitution between wealth \(W\) and liquidity service \(\ell\)). Bank \(i\)'s deposit spread at \(t\) is \(s_{it}=f_t-r_{it}^{dep}\) (\(f_t\) the Fed funds rate, \(r^{dep}\) the deposit rate). Proposition: with \(\rho<1<\varepsilon,\eta\) (\(\eta\) the cross-bank elasticity), \(\mathcal M=1-(\eta-1)(N-1)\) capturing banks' deposit market power, as \(\lambda\to0\), if \(\mathcal M<\rho\) the spread is zero, otherwise

$$s=\delta^{\frac1{\varepsilon-1}}\left(\frac{\mathcal M-\rho}{\varepsilon-\mathcal M}\right)^{\frac1{\varepsilon-1}}f$$

the spread \(s\) increases in market power \(\mathcal M\), increases in the Fed funds rate \(f\), and increases more in \(f\) when \(\mathcal M\) is higher.

Empirics: (1) a time-series regression \(\Delta y_{it}=\alpha_i+\beta_i\Delta f_t+\xi_{it}\) by county Herfindahl percentile (Figure 21.16: higher market power → more insensitive deposit rate = more sensitive spread); (2) a within-bank regression \(\Delta y_{ijct}=\alpha_i+\delta_{jt}+\zeta_c+\lambda_{st}+\gamma\Delta f_t\times HHI_c+\varepsilon_{ijct}\) (the bank-time FE \(\delta_{jt}\) makes \(HHI_c\) exogenous: multi-branch banks shift funds across branches to meet demand, ruling out demand factors; Figures 21.17, 21.18 contraction → higher spread and deposit outflow); (3) a county-level \(y_{ct}=\alpha_c+\delta_t+\beta HHI_{c,t-1}+\gamma\Delta f_t\times HHI_{c,t-1}+\varepsilon_{ct}\) (Figure 21.19 contraction → less new lending, slower employment/wage growth); (4) a bank-level \(\Delta y_{it}=\alpha_i+\delta_t+\beta HHI_{i,t-1}+\gamma\Delta f_t\times HHI_{i,t-1}+\varepsilon_{it}\) (Figure 21.20 contraction → less deposit, more wholesale funding, smaller assets, less real-estate lending). An interesting question: where does the deposit outflow go during contraction? (Relevant to shadow banking.)

21.3.1 Relationship Lending Pre- and Post-IPO: Schenone (2010)

Schenone (2010) 定义新的银企关系度量、分析关系如何影响贷款利率(信贷价格)。数据:美国公司 IPO(SDC)+ 贷款(Dealscan,100,000 USD or more)1998–2003。关系度量:\(\text{Prior by Lead}_{i,l}\)=贷款 \(l\) 的牵头行此前参与过的公司 \(i\) 的贷款总数;\(\text{Loans to Data}_{i,l}\)=公司 \(i\) 至贷款 \(l\) 的累计贷款数;关系强度

$$\text{Intensity}_{i,l}\equiv\frac{\text{Prior by Lead}_{i,l}}{\text{Loans to Data}_{i,l}} \tag{21.10}$$

两股相反力量:(1) 信息处理效应——关系发展使贷方信息优势增、公司信贷竞争降→关系贷方抽更多信息租→借款利率随强度;(2) 信息溢出效应——公司特定信息溢出至非贷方→逆向选择减、竞争升→借款利率随强度设计:利用 IPO 引致的「外生」信息冲击(IPO 前无可信渠道披露、逆向选择重、关系贷方利用信息垄断;IPO 后受披露监管、无法保密)。主回归 \(\text{Spread}_{i,l}=\beta_0+\beta_1(\text{Intensity}\times\text{After IPO})+\beta_2(\text{Intensity}\times\text{After IPO})^2+\beta_3(\text{Intensity}\times\text{Before IPO})+\beta_4(\text{Intensity}\times\text{Before IPO})^2+\beta_5\text{After IPO}+\beta_6\text{Switched Lenders}+\beta_7\text{First Loan}+\boldsymbol\gamma'\mathbf X+\phi_{l,t}+\phi_i+\varepsilon\)(\(\text{Spread}\)=All-in Spread Drawn)。结果(图 21.21):IPO 前利差对强度呈「U」形(\(\beta_3<0,\beta_4>0\):低强度时信息溢出主导→降息维持关系,高强度时信息处理主导→抽更多租);IPO 后单调下降(\(\beta_1<0\)、\(\beta_2\) 不显著:信息不对称消失,关系仅在低借款成本时才频繁)。

Tip

Remark 21.1 关系贷方在缺乏足够信贷竞争时通过收更高利率抽信息租。这未必坏——按 Petersen-Rajan (1995),允许关系锁定可提高事前信贷可得性。但当信息不对称消失(IPO 后)竞争加剧,关系贷方须提供更低成本贷款以维持关系。

Schenone (2010) defines a new measure of bank-firm relationship and analyzes how it affects the loan interest rate (price of credit). Data: U.S. corporate IPOs (SDC) + loans (Dealscan, 100,000 USD or more) 1998–2003. Relationship measure: \(\text{Prior by Lead}_{i,l}\) = the total number of firm \(i\)'s loans the lead bank of loan \(l\) has previously participated in; \(\text{Loans to Data}_{i,l}\) = firm \(i\)'s cumulative loans up to loan \(l\); the relationship intensity

$$\text{Intensity}_{i,l}\equiv\frac{\text{Prior by Lead}_{i,l}}{\text{Loans to Data}_{i,l}} \tag{21.10}$$

Two opposite forces: (1) the information-processing effect — as the relationship develops the lender's information advantage rises and the firm's credit competition falls → the relationship lender extracts more information rent → the borrowing rate rises in intensity; (2) the information-spillover effect — firm-specific information spills over to non-lenders → adverse selection falls, competition rises → the borrowing rate falls in intensity. Design: exploit the "exogenous" information shock from an IPO (before the IPO there's no credible disclosure channel, adverse selection is severe, the relationship lender exploits its info monopoly; after the IPO firms are subject to disclosure regulation, can't keep info private). Main regression \(\text{Spread}_{i,l}=\beta_0+\beta_1(\text{Intensity}\times\text{After IPO})+\beta_2(\text{Intensity}\times\text{After IPO})^2+\beta_3(\text{Intensity}\times\text{Before IPO})+\beta_4(\text{Intensity}\times\text{Before IPO})^2+\beta_5\text{After IPO}+\beta_6\text{Switched Lenders}+\beta_7\text{First Loan}+\boldsymbol\gamma'\mathbf X+\phi_{l,t}+\phi_i+\varepsilon\) (\(\text{Spread}\) = All-in Spread Drawn). Results (Figure 21.21): pre-IPO the spread is "U"-shaped in intensity (\(\beta_3<0,\beta_4>0\): at low intensity spillover dominates → lower rate to maintain the relationship; at high intensity processing dominates → extract more rent); post-IPO it monotonically declines (\(\beta_1<0\), \(\beta_2\) insignificant: asymmetry disappears, the relationship is frequent only when the borrowing cost is low).

Tip

Remark 21.1 The relationship lender extracts information rent by charging a higher rate when there is no strong credit competition. This isn't necessarily bad — per Petersen-Rajan (1995), allowing relationship lockup can increase ex-ante credit availability. But when competition intensifies as information asymmetry disappears (after the IPO), the relationship lender must provide lower-cost loans to maintain the relationship.

21.3.2 Manipulating Ratings Before Information Sharing: Giannetti et al. (2017)

Giannetti et al. (2017) 表明:在通过公共信贷登记与竞争者共享数据之前,银行操纵借款人评级(下调高质量、上调低质量)以保护自己的信息租。信贷登记(公共、央行/监管管理)vs 信贷局(私营商业)。背景:阿根廷公共信贷登记扩张——1991 起建立,金融机构报贷款额、抵押、私有评级(整数 1–5,1 最佳;1/2 由各银行私定,极有信息量:评级 1 违约 3.6%、评级 2 违约 21%);央行原以磁带(昂贵)每月仅报总贷款额more than 200,000 USD 或评级 3/4/5 的借款人。1998 年 4 月宣布改用 CD-ROM(便宜)共享全部借款人月度信息→信息共享大增。聚焦过渡期(宣布后、实施前,1998.4–6,银行尚未观测他行共享信息、无学习)。

设计:聚焦改革公告前总贷款 150,000–250,000 USD 的借款人(受影响组 = 总借款below 200,000 USD 的高质量者;200,000–250,000 USD 信息已公开→对照)。两组:Group 1 单一关系、评级 1(最高信息租、最强下调激励);Group 2 多关系、评级 2。DiD(OLS):

$$\text{Downgrade}_{i,b,t}^{1\to2}=\beta_0+\beta_1\text{Treated}_i+\beta_2\text{Treated}_i\times\text{Interim}_t+\beta_3\text{Treated}_i\times\text{Post}_t+\beta_4\text{Treated}_i\times\text{Interim}_t\times\text{Local}_b+\beta_5\text{Treated}_i\times\text{Post}_t\times\text{Local}_b+\boldsymbol\gamma_1'\mathbf X_{b,t}+\boldsymbol\gamma_2'\mathbf X_{i,t}+\xi_t+\lambda_b+\phi_{b,t}+\varepsilon \tag{21.11}$$

战略上调(Group 2)同形 (21.12);银企关系变化 \(y_t=\beta_0+\beta_1\text{Treated}_i+\beta_2\text{Treated}_i\times\text{Post}_t+\psi_i+\chi_{d,t}+\boldsymbol\gamma'\mathbf X_{i,t}\) (21.13)(\(y\)=债务总额、关系数、本地/外资银行占比)。结果:(1) 战略下调高质量借款人——银行在过渡期更可能下调单一关系评级 1 者以保信息租(实施后不发生=学习/竞争开始;主由本地银行驱动;图 21.22、21.23);(2) 战略上调低质量借款人——银行在过渡期更可能上调多关系评级 2 者以避债权人挤兑(实施后所有债权人见坏评级会挤兑,故给坏评级的银行有动机藏之;图 21.24);(3) 关系变化——实施后高质量单一关系借款人从本地(关系借贷)转向外资(交易借贷),多关系借款人增加关系数(图 21.25)。

Giannetti et al. (2017) show that before sharing data with competitors via a public credit registry, banks manipulate borrowers' ratings (downgrade high-quality, upgrade low-quality) to protect their own information rent. Credit registry (public, run by central banks/supervisors) vs credit bureau (private, commercial). Background: Argentina's public-credit-registry expansion — established 1991, institutions report loan amount, collateral, private ratings (integers 1–5, 1 best; 1/2 privately decided, very informative: default 3.6% for rating 1, 21% for rating 2); the central bank originally used magnetic tapes (costly) to report monthly only borrowers with total loans more than 200,000 USD or ratings 3/4/5. In April 1998 it announced a switch to CD-ROMs (cheaper) sharing all borrowers' monthly info → greatly improved sharing. Focus on the interim period (after announcement, before implementation, April–June 1998, when banks haven't observed others' shared info, no learning).

Design: focus on borrowers with total loans 150,000–250,000 USD before the announcement (the affected group = high-quality borrowers with total borrowing below 200,000 USD; info on 200,000–250,000 USD was already public → control). Two groups: Group 1 single-relationship, rating 1 (highest rent, strongest downgrade incentive); Group 2 multiple-relationship, rating 2. DiD (OLS):

$$\text{Downgrade}_{i,b,t}^{1\to2}=\beta_0+\beta_1\text{Treated}_i+\beta_2\text{Treated}_i\times\text{Interim}_t+\beta_3\text{Treated}_i\times\text{Post}_t+\beta_4\text{Treated}_i\times\text{Interim}_t\times\text{Local}_b+\beta_5\text{Treated}_i\times\text{Post}_t\times\text{Local}_b+\boldsymbol\gamma_1'\mathbf X_{b,t}+\boldsymbol\gamma_2'\mathbf X_{i,t}+\xi_t+\lambda_b+\phi_{b,t}+\varepsilon \tag{21.11}$$

strategic upgrade (Group 2) has the same form (21.12); the lending-relationship change \(y_t=\beta_0+\beta_1\text{Treated}_i+\beta_2\text{Treated}_i\times\text{Post}_t+\psi_i+\chi_{d,t}+\boldsymbol\gamma'\mathbf X_{i,t}\) (21.13) (\(y\) = total debt, number of relationships, local/foreign bank shares). Results: (1) strategic downgrade of high-quality borrowers — banks are more likely to downgrade single-relationship rating-1 borrowers in the interim to protect rent (not post-implementation = learning/competition start; primarily driven by local banks; Figures 21.22, 21.23); (2) strategic upgrade of low-quality borrowers — banks are more likely to upgrade multiple-relationship rating-2 borrowers in the interim to avoid a creditor run (after implementation all creditors see the bad rating and would run, so the bank giving the bad rating hides it; Figure 21.24); (3) relationship changes — after implementation, high-quality single-relationship borrowers shift from local (relationship) to foreign (transactional) banks, and multiple-relationship borrowers increase their number of relationships (Figure 21.25).

References