Commercial Real Estate Lending: Banks Potentially Face Increased Risk; Regulators Generally Are Assessing Banks' Risk Management Practices
Released: 2018-03-15T00:00:00

Letter

Background

Federal Banking Supervision

The purpose of federal banking supervision is to help ensure that banks throughout the financial system are operating in a safe and sound manner and are complying with banking laws and regulations in the provision of financial services. Banks in the United States are supervised by one of the following three federal regulators:

FDIC supervises all FDIC-insured state-chartered banks that are not members of the Federal Reserve System and insured state savings associations and insured state chartered branches of foreign banks.

The Federal Reserve supervises commercial banks that are state- chartered and members of the Federal Reserve System.

OCC supervises federally chartered national banks and savings associations (also known as federal thrifts).

FDIC, the Federal Reserve, and OCC are required to conduct a full- scope, on-site examination of each of their supervised banks at least once during each 12-month period. The regulators may extend the examination interval to 18 months, generally for banks and thrifts that have less than $1 billion in total assets and that meet certain conditions, such as satisfactory ratings, are well capitalized, and are not being subject to a formal enforcement action. As part of a full-scope examination, examiners review a bank’s risk exposure within a number of components using the Uniform Financial Institutions Rating System, which also is referred to as the CAMELS rating system (capital adequacy, asset quality, management, earnings, liquidity, and sensitivity to market risk). Evaluations of CAMELS components consider a bank’s size and sophistication, the nature and complexity of its activities, and its risk profile.

The end result of a full-scope, on-site examination is a report of examination, which includes the CAMELS ratings and other findings and is provided to the bank’s management and board of directors. A report of examination may include deficiencies or other issues that examiners found and that a bank is expected to address within specific time frames. Such issues generally are called supervisory recommendations by FDIC, supervisory findings by the Federal Reserve, and supervisory concerns by OCC. For purposes of this report, we collectively refer to such issues as supervisory concerns. Supervisory concerns may be designed to correct practices that deviate from sound risk management principles or noncompliance with laws and regulations. Supervisory concerns that involve more significant issues are brought to the attention of a bank’s board of directors and senior management in the report of examination as matters requiring immediate attention (MRIA) or matters requiring attention (MRA) under the Federal Reserve’s policies, matters requiring board attention (MRBA) under FDIC’s policies, and MRAs under OCC’s policies. If a bank were to fail to address a supervisory concern, its regulator could subject the bank to enhanced supervision, downgrade of a component or composite rating, or other supervisory actions, such as informal or formal enforcement actions.

CRE Lending and Associated Risks

Under their 2006 guidance, regulators define CRE loans to include construction loans, loans to finance CRE that are not secured by CRE, loans secured by multifamily property, and loans secured by nonfarm, nonresidential property in which the primary source of repayment derives from the rental income associated with the property or the proceeds of the sale, refinancing, or permanent financing of the property. CRE loans in which the primary source of repayment is not the property itself are called owner-occupied loans and can include loans to businesses for working capital purposes that use real estate as collateral. For example, a line of credit for a business’s operating expenses might be secured in part by commercial property, such as an office.

Construction and land development (CLD) loans generally are considered to be the riskiest class of CRE, due to their long development times and because they can include properties (such as housing developments or retail space in a shopping mall) that are built before having firm commitments from buyers or lessees. In addition, by the time the construction phase is completed, market demand may have fallen, putting downward pressure on sales prices or rents—making this type of loan more risky.

Regulatory Guidance on CRE Concentrations and Risk Management Practices

Based on concerns about the increase in CRE concentrations at community banks and the risks associated with such concentrations, FDIC, the Federal Reserve, and OCC jointly issued guidance in December 2006 on CRE concentrations and sound risk management practices. The guidance described the regulators’ expectations for sound risk management practices for banks with concentrations in CRE loans. Specifically, the guidance identified seven key elements, or internal control areas, that a bank’s risk management practices should address to identify, monitor, and control its CRE concentration risk (see fig. 1).

The 2006 CRE guidance also sets forth three criteria to identify banks with CRE loan concentrations that could be subject to greater supervisory scrutiny. According to the guidance, a bank that has experienced rapid growth in CRE lending, has notable exposure to a specific type of CRE, or is approaching or exceeds the following supervisory criteria may be identified for further supervisory analysis of the level and nature of its CRE concentration risk:

CLD concentration threshold: CLD loans represent 100 percent or more of a bank’s total capital.

Total CRE concentration threshold: Total nonowner-occupied CRE loans (including CLD loans) represent 300 percent or more of a bank’s total capital and total CRE lending increased by 50 percent or more during the previous 36 months.

According to the guidance, the CLD and CRE thresholds do not constitute limits on a bank’s CRE lending activity but rather serve as high-level indicators to identify banks potentially exposed to CRE concentration risk.

In 2011, we reported on how the federal banking regulators had responded to the potential risks of growing CRE concentrations at community banks, including by jointly issuing the 2006 CRE concentration guidance. We recommended that the regulators should enhance or supplement the 2006 CRE guidance and take steps to better ensure that such guidance is consistently applied. The regulators have taken steps to address our recommendation.

Out of the approximately 5,900 banks that had a CRE loan portfolio as of the end of June 2017, a total of 504 banks exceeded either 100 percent in CLD loans as a percentage of total risk-based capital, or 300 percent in CRE loans as a percentage of total-risk based capital and had seen 50 percent CRE portfolio growth during the previous 36 months. Of these 504 banks, a total of 69 banks exceeded both the CLD criteria and the total CRE criteria (including the growth component).

In December 2015, federal banking regulators issued a joint statement to remind banks of the 2006 regulatory guidance on prudent risk management practices for CRE lending activity through economic cycles. The regulators noted, among other trends, that many banks’ CRE concentration levels had been rising. According to the statement, regulators would continue to pay special attention to potential risks associated with CRE lending during 2016. Specifically, the regulators stated that when conducting examinations that include a review of CRE lending activities, they would focus on banks’ implementation of the prudent principles in the 2006 CRE guidance and other applicable guidance relative to identifying, measuring, monitoring, and managing concentration risk in CRE lending activities.

According to officials from FDIC, the Federal Reserve, and OCC, their agencies use a variety of formal and informal processes to monitor the condition of banks and identify risks, including CRE concentration risk. For example, The Federal Reserve has a National Risk Council and FDIC and OCC have National Risk Committees that meet routinely to identify and evaluate risks facing banks and are supported by a number of other committees or other groups. FDIC officials told us that analysis done by FDIC’s Regional Risk Committees identified growth in CRE concentrations in 2015 and brought the issue to the National Risk Committee’s attention. OCC began actively monitoring CRE loan growth in the middle of 2014 and began focusing on CRE concentration risk management during bank examinations in 2015. OCC officials also stated that CRE concentration risk has been a key risk issue for the agency’s National Risk Committee since early 2016. Federal Reserve officials told us that the agency, including the Federal Reserve banks, began to monitor bank CRE concentrations more closely around mid-2013 after identifying an increase in CRE concentrations. According to FDIC, Federal Reserve, and OCC officials, they met together in early 2015 to discuss CRE lending growth and the rise in bank CRE loan concentrations and held subsequent meetings throughout the year, in part to discuss policy options for helping to ensure that banks were appropriately managing their CRE concentration risks. One of the outcomes of such interagency coordination was the December 2015 joint statement on CRE concentrations.

Credit and Other Risks Related to Bank CRE Lending Have Increased over the Past Several Years

Although the CRE sector has recovered since the 2007–2009 financial crisis, our trend and econometric analyses generally indicate that credit and other risks related to bank CRE lending have increased over the past several years.

Based on indicators of CRE market conditions and loan performance, the CRE sector has recovered from the 2007–2009 financial crisis. For example, spending on CRE construction projects—a source of demand for bank financing—has rebounded. Vacancy rates for apartments, office buildings, and other CRE properties have declined. Similarly, as shown in figure 2, delinquency and charge-off rates on bank CRE loans have fallen from their post-crisis peaks and are at or below their lowest levels since 2002. Although these rates provide information on the current performance of bank CRE loans, they provide little or no information about potential future risks faced by banks. For example, high-risk loans made to less creditworthy borrowers could perform well when property markets and the economy are doing well but may perform poorly when property markets or the economy begin to slow.

At the same time, our analyses of other market, underwriting, and lending data and forecasts from predictive econometric models we developed suggest that banks’ credit and concentration risks related to their CRE lending have increased. As shown in figure 3, according to a Federal Reserve survey, banks lowered their CRE loan underwriting standards— terms and conditions under which banks extend loans—after the financial crisis, but more banks began to tighten their underwriting standards since late 2015. In general, tightening underwriting standards may indicate that loan officers are reevaluating the degree of risk in CRE markets served by banks. According to Federal Reserve data, a larger share of banks has tightened underwriting standards on multifamily properties, such as apartments.

CRE property prices, particularly for multifamily properties, have increased rapidly in recent years, and CRE property valuations have similarly increased. For example, as shown in figure 4, capitalization rates (the ratio of income generated by a property to the property’s price) on CRE properties have trended downward since around 2010—indicating that borrowers (i.e., property owners) may be earning less of a return on their CRE properties. Capitalization rates can be indicative of expected future price changes—for example, low capitalization rates may reflect expectations of future price increase, but can also be driven by investor sentiment not associated with fundamental aspects of properties.

In addition, as shown in figure 5, the number of banks with concentrated portfolios in CLD or total CRE loans has been gradually increasing since around 2014. Greater concentrations in a particular lending sector (e.g., commercial real estate, residential real estate, or business lending) leave banks more vulnerable to a sectoral downturn, all else equal.

To further assess risk in bank CRE lending, we developed and estimated several predictive models of aggregate losses on bank CRE loans. The models incorporate measures of CRE property prices, bank lending, and underwriting standards. The models generally found that, historically, higher future losses are predicted when CRE lending and prices are simultaneously high relative to gross domestic product, and when banks are tightening underwriting standards. Based largely on the simultaneous increase in bank CRE lending and CRE prices observed over the last several years, these models suggest that credit risk has increased, though it remains lower than the level of risk associated with the 2007– 2009 financial crisis. As we noted earlier, high property valuations and substantial increases in lending can simultaneously weaken collateral protections and indicate lower borrower quality, both of which can raise the risk of losses should the economy or CRE sector weaken. (See app. II for additional information on our models.)

Regulators Examined Risk Management Practices of Banks with CRE Concentrations

We found that regulators generally subjected banks with relatively high concentrations in CRE loans to greater supervisory scrutiny in comparison to banks with relatively lower concentrations in CRE loans in our review of 54 examinations for 40 banks conducted from 2013 through 2016. In all of these examinations, the regulators specifically assessed whether each bank had adequate risk management practices and capital for managing its CRE concentration risk and generally found that the banks had adequate risk management practices and capital. In a few examinations, regulators differed in how they addressed supervisory concerns about a bank’s CRE-related risk management practices.

Regulators Examined Whether Banks with Relatively High CRE Concentrations Had Adequate Practices and Capital to Manage Their CRE Concentration Risk

In our review of a nongeneralizable sample of 54 examinations conducted from 2013 through 2016, we found that FDIC, Federal Reserve, and OCC subjected banks with relatively high concentrations in CRE loans to greater supervisory scrutiny. In both their 2006 CRE guidance and 2015 CRE statement, the regulators indicated that banks with relatively high CLD or total CRE concentrations should maintain risk management practices commensurate with the level and nature of their concentration risk. The 2006 CRE guidance recognized that the sophistication of a bank’s CRE risk management practices depends on, among other things, the level and nature of its CRE concentrations and associated risk. As noted earlier, the guidance notes that a bank’s risk management practices should address seven internal control areas: (1) board and management oversight; (2) portfolio management; (3) management information systems; (4) market analysis; (5) credit underwriting standards; (6) portfolio stress testing and sensitivity analysis; and (7) credit risk review function. Based on our analyses, we found that the 2006 CRE guidance’s risk management framework is adequately designed to help ensure that banks effectively identify, measure, monitor, and control their CRE concentration risk. For example, the guidance is consistent with credit and concentration risk principles issued by international standard- setting bodies.

Of the 54 reports of examination that we reviewed, 41 of them covered banks whose CLD or total CRE concentrations exceeded the CLD concentration threshold, total CRE concentration threshold, or both thresholds set forth in the 2006 guidance. In all of these examinations, we found that FDIC, Federal Reserve, and OCC examiners generally assessed whether each bank had implemented adequate risk management practices to manage their concentration risk. As shown in figure 6, in 26 of the 41 examinations, FDIC, Federal Reserve, and OCC examiners did not find any weaknesses in the banks’ CRE risk management practices across the seven internal control areas, but did find weaknesses in the remaining 15 examinations.

In 15 of the 41 examinations we reviewed, FDIC, Federal Reserve, and OCC examiners found the banks had CRE-related risk management weaknesses in at least one of the seven internal control areas. Examiners most frequently found risk management weakness in three internal control areas: board and management oversight (11 instances), management information systems (8 instances), and stress testing (7 instances). To a slightly lesser extent, examiners found weaknesses in portfolio management, credit underwriting standards, and credit risk review function. Examiners communicated their supervisory concerns to these 15 banks in their reports of examinations.

In 12 of the examinations, examiners included MRAs, MRBAs, or MRIAs in their reports of examination that directed the banks to correct their risk management weaknesses.

In the other three examinations, examiners included recommendations or other notes in their reports of examination that generally directed the banks to correct their risk management weaknesses.

Consistent with the 2006 CRE guidance, we found that examiners generally did not use the CLD or total CRE concentration thresholds as limits on bank CRE lending. With two exceptions, examiners did not direct banks that exceeded the CLD or CRE threshold to reduce their concentrations but rather focused on ensuring that the banks’ risk management practices were commensurate with the nature and level of their concentration risk. In the two exceptions, examiners found the banks’ practices and capital inadequate for managing their CLD or CRE concentration risk and directed the banks to reduce their concentrations and improve their risk management practices.

We found that FDIC, Federal Reserve, and OCC examiners varied in the extent to which they documented—in the reports of examination and supporting workpapers—the scope of their review of banks’ CRE-related risk management practices and findings. For example, we were not always able to determine whether examiners found a bank’s practices adequate in one or more of the seven internal control areas based on our review of the report of examination and, if available, supporting workpapers. According to the regulators, reports of examinations are used primarily to document practices found to be inadequate and not practices found to be adequate. Moreover, the regulators told us that their examiners recently have been required to use a CRE examination module to document their assessment and findings of banks with concentrations exceeding the CLD or CRE threshold.

Capital and Concentration Risk

In the 41 examinations we reviewed where banks exceed one of the concentration thresholds, FDIC, Federal Reserve, and OCC examiners assessed whether the banks generally had capital commensurate with their CRE concentration risk. In 34 of the examinations, examiners determined that the banks’ capital levels were adequate for managing their CLD or total CRE concentration risk. In 7 of the examinations, examiners determined that the banks’ capital levels were inadequate. For six of the seven banks, examiners directed the banks in the reports of examination to reduce or manage their CRE concentrations in light of inadequate capital. In the case of one bank, examiners required the bank to comply with a previous formal enforcement action that addressed the need for the bank to adhere to its board-approved capital plan.

Review of CRE-Related Risk Management Practices in Subsequent Examination Cycles

For banks with relatively high CLD or total CRE concentrations, we found that Federal Reserve and OCC examiners assessed the banks’ CRE- related risk management practices in subsequent examinations. In our review of 41 examinations of banks that exceeded the CLD or CRE threshold, 26 of them covered two examination cycles of 13 banks conducted from 2013 through 2016. We found that examiners assessed the banks’ practices for managing their concentration risk in both examinations.

In 14 examinations (covering 7 banks), examiners found that the banks had adequate risk management practices in both examinations.

In six examinations (covering three banks), examiners found aspects of the banks’ risk management practices to be inadequate in their 2013 or 2014 examination and noted their supervisory concerns in the reports of examination. In the subsequent examinations, the examiners found that the banks had adequately addressed the previously identified risk management weaknesses.

In six examinations (covering three banks), examiners found the banks’ practices for managing their CRE concentration risk to be adequate in the 2013 or 2014 examinations but inadequate in the subsequent examinations. The examiners issued the banks MRAs or MRIAs or took an informal enforcement action.

Regulators Generally Did Not Examine CRE-Related Risk Management Practices of Banks with Concentrations below the CLD or Total CRE Threshold

For banks with concentrations below the CLD or total CRE threshold, we found that regulators generally did not examine the banks’ CRE-related risk management practices. Thirteen of the 54 examinations we reviewed covered banks that did not exceed the CLD or CRE thresholds. Although the banks did not exceed either threshold, OCC examiners assessed the banks’ CRE-related risk management practices in 3 of the examinations. In 1 examination, examiners determined that the bank’s CRE-related risk management practices were adequate. The other 2 examinations covered subsequent cycle examinations of the same bank. In the first examination, examiners found that the bank had adequate practices for managing risk associated with its CRE loans but directed the bank through an MRA to incorporate stress testing of the loan portfolio into its monitoring. In the subsequent examination, the examiners found that the bank had addressed the MRA. In the other 10 examinations, FDIC, Federal Reserve, and OCC examiners did not mention in the report of examination the banks’ practices for managing the risk associated with their CRE loans.

FDIC, Federal Reserve, and OCC officials told us that examiners use their professional judgment in determining whether to review a bank’s CRE-related risk management practices if the bank’s concentration is below the CLD and CRE threshold. This approach is consistent with the overall risk-based supervisory process used by the regulators, which focuses examiner resources on assessing bank management’s ability to identify and control risks. For example, FDIC’s examination guidelines note that examiners should focus their resources on a bank’s highest risk areas when assessing risk management programs, financial conditions, and internal controls. According to the guidance, the exercise of examiner judgment to determine the scope and depth of review in each functional area is crucial to the success of the risk-focused supervisory process.

Regulators Differed in How They Addressed a Few Supervisory Concerns about Banks’ CRE-Related Risk Management Practices

In a few examinations, we found differences across regulators in how they addressed supervisory concerns about banks’ CRE-related risk management practices because of differences in the regulators’ policies. In our nongeneralizable sample of 54 examinations, Federal Reserve, FDIC, and OCC examiners included CRE-related supervisory concerns, such as recommendations, MRAs, or MRBAs, in 22 of the reports of examinations. Although the regulators have policies for identifying and communicating supervisory concerns, their policies use different criteria. For example, OCC’s policies instruct examiners to use MRAs to describe practices that a bank must implement or correct to address a deficiency and not to use MRAs to require enhancements to bank practices that meet acceptable standards. However, the Federal Reserve’s and FDIC’s policies do not expressly include such criteria. Consistent with their policies, OCC examiners included MRAs in the reports of examination that we reviewed only when they found a bank’s CRE-related risk-management practices to be inadequate. In contrast, in 2 reports of examination, we found that FDIC examiners did not find the banks’ CRE- related risk management practices to be inadequate but included MRBAs to direct the banks to enhance or sustain certain CRE-related risk management practices. Similarly, in 1 report of examination, Federal Reserve examiners found that the bank’s risk management practices and capital were adequate for its CRE concentrations but included an MRA to require the bank to enhance its capital plan to include concentration risk considerations.

FDIC, Federal Reserve, and OCC Have Recently Taken Formal Enforcement Actions against Banks for Not Adequately Managing Their CRE Concentration Risk

In addition to their examinations, federal banking regulators have taken informal and formal enforcement actions against banks for not adequately managing their CRE concentration risk. In general, initial consideration and determination of whether informal or formal action is required usually results from examination findings. Unlike informal enforcement actions, formal enforcement actions are published or publicly available. From 2013 through 2016, FDIC, the Federal Reserve, and OCC took formal enforcement actions against banks for not adequately managing risks related to their CRE concentrations, including those outlined in the jointly issued 2006 CRE guidance.

FDIC took 22 formal enforcement actions against banks for matters related to their CRE concentrations during this period.

The Federal Reserve took 2 formal enforcement actions against banks for matters related to their risk management of CRE lending.

OCC took 11 formal enforcement actions against banks for matters related to their CRE concentrations during this same period.

The majority of these formal enforcement actions discussed the 2006 CRE guidance and directed the banks to improve their practices for managing their CRE concentration risk. For example, in a number of formal enforcement actions, the regulators ordered the banks to revise their written concentration risk management programs for identifying, monitoring, and controlling risks associated with concentrations of credit, consistent with the 2006 CRE guidance.

Agency Comments

We provided a draft of this report to FDIC, the Federal Reserve, and, OCC for review and comment. The agencies provided technical comments, which we incorporated as appropriate.

We are sending copies of this report to the appropriate congressional committees and FDIC, the Federal Reserve, and OCC. This report will also be available at no charge on our website at http://www.gao.gov.

Should you or your staff have questions concerning this report, please contact me at (202) 512-8678 or evansl@gao.gov. Contact points for our Offices of Congressional Relations and Public Affairs may be found on the last page of this report. Key contributors to this report are listed in appendix VII.

Appendix I: Objectives, Scope, and Methodology

Our objectives in this report were to examine: (1) trends in the commercial real estate (CRE) lending markets, including changes in the level of credit and concentration risk in the markets, and (2) actions federal banking regulators took through their examinations to help ensure that banks with CRE concentrations are effectively managing the related risks.

To examine trends in the CRE lending markets, we reviewed academic literature and prior GAO work and interviewed officials from the federal banking regulators and private data providers. Specifically, we interviewed officials at the Board of Governors of the Federal Reserve System (Federal Reserve), the Federal Deposit Insurance Corporation (FDIC), and the Office of the Comptroller of the Currency (OCC) to help identify potential indicators of risk in CRE markets. To further inform our assessment of risk, we reviewed prior GAO work on the lessons learned from prior banking crises and the use of early warning models for monitoring the financial system. We also reviewed academic research on early warning models of banking and real estate-related crises.

To report trends and assess risk, we reviewed and analyzed a range of data that we considered to be reflective of various aspects of risk in CRE lending markets. Specifically, we reviewed and analyzed commercial property vacancy data from REIS (a private commercial real estate data provider); commercial property construction data from the U.S. Census Bureau; data on delinquencies and charge-offs on bank CRE loans from the Federal Reserve; data on commercial property prices and capitalization rates from Real Capital Analytics (a private commercial real estate data provider); FDIC data on bank CRE lending; and Federal Reserve data on underwriting standards. We evaluated trends in these data and used a subset of these data to estimate several predictive models of aggregate losses on bank CRE loans. (See app. II for more information on our predictive models.)

To examine actions taken by federal regulators to help ensure that banks with high CRE concentrations are effectively managing the related risks, we reviewed and analyzed their relevant guidance and regulations on bank CRE lending, examination policies and procedures (e.g., examination manuals and modules), studies and other publications on risks in the banking industry, and formal enforcement actions taken from 2013 through 2016 for CRE-related matters. In addition, we analyzed Consolidated Reports of Condition and Income data from SNL Financial for the period from 2011 through 2016 to calculate banks’ construction and land development (CLD) and CRE concentrations during the period. Specifically, we used the concentration formulas in the 2006 CRE concentration guidance (jointly issued by the federal banking regulators) to calculate banks’ CLD and CRE concentrations and identify banks whose CRE concentrations exceeded, in full or in part, the guidance’s CRE concentration thresholds during part or all of the time frame. Based on whether the banks’ CRE concentrations exceeded the thresholds and other criteria discussed below, we selected a nongeneralizable sample of 40 banks overseen by FDIC, the Federal Reserve, or OCC. For the banks in our sample, we requested from the regulators copies of the reports of examination and, if available, related workpapers prepared by the regulators based on their full-scope examinations of the banks done from 2013 through 2014, and from 2015 through 2016.

In addition to using banks’ CRE concentrations as a basis to select examinations, we judgmentally selected a nonprobability sample of banks based on the following criteria:

Total asset size: We considered the size of the banks based on their total assets and selected banks from each of the following three ranges: (1) banks with $1 billion or more in total assets, (2) banks with $100 million or more but less than $1 billion in total assets, and (3) banks with less than $100 million in total assets.

Primary regulator: We considered the primarily regulator of the banks and selected a sample of 40 banks that resulted in a total of 20 examinations to review from each regulator.

Geographic distribution: We selected banks to ensure that at least one bank was from each of the four regions of the U.S. Census and each of the nine divisions within those regions.

Based on the 40 banks we selected, we reviewed and analyzed 54 reports of examination and, if available, the related workpapers. We analyzed the examinations using criteria or other requirements specified in the 2006 CRE guidance jointly issued by the regulators and their examination policies and procedures. We did not review six examinations of banks supervised by the Federal Reserve. We also interviewed officials from FDIC, Federal Reserve, and OCC, and from a national banking association about bank CRE lending and applicable CRE guidance and requirements.

For the data we analyzed under both of our objectives, we took a number of steps to assess the reliability of the data, including interviewing data providers; corroborating trends across multiple data sources; reviewing related documentation; inspecting data for missing values, outliers, or other errors; and reviewing relevant, prior GAO work. We determined that these data were sufficiently reliable for our reporting objectives.

We conducted this performance audit from January 2017 to March 2018 in accordance with generally accepted government auditing standards. Those standards require that we plan and perform the audit to obtain sufficient, appropriate evidence to provide a reasonable basis for our findings and conclusions based on our audit objectives. We believe that the evidence obtained provides a reasonable basis for our findings and conclusions based on our audit objectives.

Appendix II: GAO Predictive Models of Aggregate Losses on Bank Commercial Real Estate Loans

We developed and estimated several models of aggregate losses on bank commercial real estate (CRE) loans. These models attempt to predict future aggregate charge-offs using contemporary indicators of potential risks. We incorporated indicators of risk based on the cross- country research literature on early warning models of banking risk and prior GAO work on identifying early warning models as tools that could assist financial regulators in assessing risk. One study summarized the overall intuition for models of this class in the following way: “imbalances manifest themselves in the coexistence of unusually rapid cumulative growth in private sector credit and asset prices.” Our results were consistent with this concept and extend the aggregate early warning model literature to a sectoral model. As such, our models incorporate measures of CRE property prices, bank lending volumes, and bank loan underwriting standards.

The models predict charge-offs 2–3 years into the future (the dependent variable is the average charge-off rate for 8 through 11 quarters into the future), using commercial bank charge-off rates from the Board of Governors of the Federal Reserve System (Federal Reserve), first quarter 1991 to second quarter 2017. (See below for an illustrative regression equation for one of these models.)

We began with two model variations, one based on the levels of key variables and the other based on their growth rates, using the following independent variables, respectively: “Level” model: Level of CRE prices to gross domestic product (GDP), level of bank CRE lending to GDP, the interaction of the level of CRE prices and lending, and the net percentage of banks tightening underwriting standards on CRE loans. “Growth” model: Growth rate of CRE prices over the last year, growth rate of bank CRE lending over the last year, interaction of price and lending growth, and the net percentage of banks tightening underwriting standards on CRE loans.

By inspection, the model based on levels also captured key aspects of the evolution of aggregate losses on bank CRE loans in recent decades—for example, low charge-offs prior to the crisis, the rapid increase during crisis, and very low charge-offs in recent years. In this model higher losses are predicted by tightening underwriting standards, and the interaction of (i.e., simultaneous increase in) the level of CRE prices and the level of CRE lending. The bulk of the explanatory power of the model appears to come from the interaction of the level of CRE prices and the level of CRE lending—consistent with Borio and Drehmann’s view that the coexistence of rapidly increasing credit and prices is associated with greater risk. These results are also consistent with a more general theory, for example, that periods of economic stability induce greater risk-taking over time, bidding up asset prices and loosening underwriting standards until ultimately increased valuations become unsustainable, prices fall, and borrowers begin to default.

We estimated a number of additional models for robustness, to determine if goodness-of-fit and forecasts could be improved markedly, and to assess the degree of forecast uncertainty. For example we estimated a model with a censored dependent variable and used information criteria to select models that combined elements from our initially separate models based on growth rates and levels as well as a model that includes current charge-offs. In figure 7, we report the general trend in expected future charge-offs as well as convey forecast uncertainty based on differences in the forecasts of three of these models.

In figure 8, we convey forecast uncertainty based on the 75 percent confidence interval for a combined model that we selected based on information criteria.

Implicit in this exercise is the assumption that the data-generating process is reasonably stable—as a result, structural change associated with new financial products, new risk management tools, and new legal and regulatory frameworks could reduce the stability of the data- generating process. We interpret our results and forecasts in light of these potential limitations. Specifically, we do not interpret model results as concrete, precise predictions of aggregate commercial real estate losses but rather as an additional, general indication of the degree of risk in bank CRE lending.

We mitigate risks associated with estimating this type of model with appropriate diagnostics, out-of-sample testing, and by developing the model in the context of the well-established early warning literature. That said, some inevitable limitations remain, including the potential omission of important risk factors and other approximations associated with our specification (e.g., our choice of a linear functional form). In addition, diagnostics for detecting nonstationary time series are imperfect, especially with small sample sizes, which may inflate our measures of statistical significance and traditional goodness-of-fit measures like r- squared. These biases may be present, however, in models that still generate useful predictions. In this “small data” context there is also risk of fitting (or over-fitting) the model to predict a particular credit event— though, again, this risk is mitigated somewhat in the context of the broad cross-country early warning literature and the use of out-of-sample testing.

Appendix III: GAO Contact and Staff Acknowledgments

GAO Contact

Staff Acknowledgments

In addition to the contact named above, Richard Tsuhara (Assistant Director), Tarek Mahmassani (Analyst in Charge), Abigail Brown, Tarik Carter, M’Baye Diagne, Michael Hoffman, Risto Laboski, Marc Molino, Jessica Sandler, Jennifer Schwartz, and Andrew Stavisky made significant contributions to this report.