Managerial Overconfidence and Corporate Policies

Miscalibration is a standard measure of overconfidence in both psychology and economics. Although it is often used in lab experiments, there is scarcity of evidence about its effects in practice. We test whether top corporate executives are miscalibrated, and whether their miscalibration impacts investment behavior. Over six years, we collect a unique panel of nearly 7,000 observations of probability distributions provided by top financial executives regarding the stock market. Financial executives are miscalibrated: realized market returns are within the executives' 80% confidence intervals only 38% of the time. We show that companies with overconfident CFOs use lower discount rates to value cash flows, and that they invest more, use more debt, are less likely to pay dividends, are more likely to repurchase shares, and they use proportionally more long-term, as opposed to short-term, debt. The pervasive effect of this miscalibration suggests that the effect of overconfidence should be explicitly modeled when analyzing corporate decision-making.

Do Hedge Funds Manipulate Stock Prices?

We find evidence of significant price manipulation at the stock level by hedge funds on critical reporting dates. Stocks in the top quartile by hedge fund holdings exhibit abnormal returns of 30 basis points in the last day of the month and a reversal of 25 basis points in the following day. Using intraday data, we show that a significant part of the return is earned during the last minutes of the last day of the month, at an increasing rate towards the closing bell. This evidence is consistent with hedge funds’ incentive to inflate their monthly performance by buying stocks that they hold in their portfolios. Higher manipulations occur with funds that have higher incentives to improve their ranking relative to their peers and a lower cost of doing so.

Multivariate Public Key Cryptosystem from Sidon Spaces

A Sidon space is a subspace of an extension field over a base field in which the product of any two elements can be factored uniquely, up to constants. This paper proposes a new public-key cryptosystem of the multivariate type which is based on Sidon spaces, and has the potential to remain secure even if quantum supremacy is attained. This system, whose security relies on the hardness of the well-known MinRank problem, is shown to be resilient to several straightforward algebraic attacks. In particular, it is proved that the two popular attacks on the MinRank problem, the kernel attack, and the minor attack, succeed only with exponentially small probability. The system is implemented in software, and its hardness is demonstrated experimentally.Comment: Appeared in Public-Key Cryptography - PKC 2021, 24th IACR International Conference on Practice and Theory of Public Key Cryptograph

The role of securitization in mortgage renegotiation

We study the effects of securitization on renegotiation of distressed residential mortgages over the current financial crisis. Unlike prior studies, we employ unique data that directly observe lender renegotiation actions and cover more than 60% of the U.S. mortgage market. Exploiting within-servicer variation in these data, we find that bank-held loans are 26% to 36% more likely to be renegotiated than comparable securitized mortgages (4.2 to 5.7% in absolute terms). Also, modifications of bank-held loans are more efficient: conditional on a modification, bank-held loans have lower post-modification default rates by 9% (3.5% in absolute terms). Our findings support the view that frictions introduced by securitization create a significant challenge to effective renegotiation of residential loans.Mortgage loans ; Asset-backed financing ; Securities ; Mortgages

Market-based loss mitigation practices for troubled mortgages following the financial crisis

The meltdown in residential real-estate prices that commenced in 2006 resulted in unprecedented mortgage delinquency rates. Until mid-2009, lenders and servicers pursued their own individual loss mitigation practices without being significantly influenced by government intervention. Using a unique dataset that precisely identifies loss mitigation actions, we study these methods—liquidation, repayment plans, loan modification, and refinancing—and analyze their effectiveness. We show that the majority of delinquent mortgages do not enter any loss mitigation program or become a part of foreclosure proceedings within 6 months of becoming distressed. We also find that it takes longer to complete foreclosures over time, potentially due to congestion. We further document large heterogeneity in practices across servicers, which is not accounted for by differences in borrower population. ; Consistent with the idea that securitization induces agency conflicts, we confirm that the likelihood of modification of securitized loans is up to 70% lower relative to portfolio loans. Finally, we find evidence that affordability (as opposed to strategic default due to negative equity) is the prime reason for redefault following modifications. While modification terms are more favorable for weaker borrowers, greater reductions in mortgage payments and/or interest rates are associated with lower redefault rates. Our regression estimates suggest that a 1 percentage point decline in mortgage interest rate is associated with a nearly 4 percentage point decline in default probability. This finding is consistent with the Home Affordable Modification Program (HAMP) focus on improving mortgage affordability.Asset-backed financing ; Financial crises ; Securities ; Mortgages