书接前文：
最近一直想系统性衡量一下各家银行账户的风险，但是信息经济学的基础知识告诉我们自愿的信息披露往往伴随着偏差，因此我想到了去找一找CFPB的数据，没想到还真有。数据在这里：https://www.consumerfinance.gov/data-research/consumer-complaints/search/ ，如果大家感兴趣可以做更多分析。
为了小试牛刀，我搜了最近一年所有有关checking/savings账户的compliants，得到了如下统计数据。我这里分享的是抱怨数量前50的银行，他们占到了所有抱怨数量的92.57%（很简单，就是pd.read, df.value_counts）。这里最重要的caveat是compliant的数量和银行客户数量是有关系的，而客户数量通常和银行市值或资产规模强相关，因此更好的统计量是number of compliants per million total assets。但我太懒了，加上我也不是做banking的不太熟别的数据，就这么参考一下好了。大家尤其要注意的是排名比较高的那些小银行，具体是谁我就不点名了，如果还在用的话可以考虑逐渐拿钱出来。
JPMORGAN CHASE & CO. 6605
WELLS FARGO & COMPANY 6398
BANK OF AMERICA, NATIONAL ASSOCIATION 4768
CITIBANK, N.A. 2742
Chime Financial Inc 2682
NAVY FEDERAL CREDIT UNION 2659
CAPITAL ONE FINANCIAL CORPORATION 2016
TRUIST FINANCIAL CORPORATION 1430
U.S. BANCORP 1346
SOFI TECHNOLOGIES, INC. 1134
PNC Bank N.A. 1099
GOLDMAN SACHS BANK USA 987
CITIZENS FINANCIAL GROUP, INC. 952
Block, Inc. 871
UNITED SERVICES AUTOMOBILE ASSOCIATION 861
TD BANK US HOLDING COMPANY 823
BMO Bank, N.A. 751
ALLY FINANCIAL INC. 653
FIFTH THIRD FINANCIAL CORPORATION 537
HUNTINGTON NATIONAL BANK, THE 513
Paypal Holdings, Inc 488
Credit Karma 440
REGIONS FINANCIAL CORPORATION 439
KEYCORP 368
M&T BANK CORPORATION 364
DISCOVER BANK 350
ROBINHOOD MARKETS INC. 332
Fidelity National Information Services, Inc. (FNIS) 320
Early Warning Services, LLC 308
AMERICAN EXPRESS COMPANY 224
SANTANDER HOLDINGS USA, INC. 217
SYNCHRONY FINANCIAL 204
Neon Newco Corporation 185
WEBSTER BANK, NATIONAL ASSOCIATION 178
Comerica 176
PENTAGON FEDERAL CREDIT UNION 172
OPTUM BANK, INC. 150
CHARLES SCHWAB CORPORATION, THE 147
FinCo Services Inc DBA Current 140
CapitalJ Inc. dba Juno 129
HSBC NORTH AMERICA HOLDINGS INC. 127
NEW YORK COMMUNITY BANCORP INC 118
AXOS FINANCIAL, INC. 115
TransferWise Ltd 108
FIRST HORIZON BANK 106
MoneyLion Inc. 104
FIRST CITIZENS BANCSHARES, INC. 97
Experian Information Solutions Inc. 91
FISERV INC. 88
Upgrade, Inc. 86
