EVIDENCE FOR RELATIONAL CONTRACTS IN SOVEREIGN BANK LENDING

This paper presents direct evidence for relational contracts in sovereign bank lending. Unlike the existing empirical literature, its instrumental variables method allows for distinguishing a direct influence of past repayment problems on current spreads (a “punishment” effect in prices) from an indirect effect through higher expected future default probabilities (“loss of reputation”). Such a punishment provides positive surplus to lenders after a default and decreases the borrower's present discounted value of the net benefits of future borrowing, which create dynamic incentives. Using data on bank loans to developing countries for 1973–1981 and constructing continuous variables for credit history, we find evidence that most of the influence of past repayment problems is through the direct, punishment channel.     

Adoption and feasibility of a communication app to enhance social connectedness amongst frail institutionalized oldest old: an embedded case study

The risks of social isolation and loneliness are becoming emergent issues for older adults (aged 65+) in industrialized countries, particularly for oldest old people (80+) who are frail and institutionalized. Socially isolated and lonely older people are more likely to experience depression, social disengagement, cognitive and physical decline, morbidity, and early mortality. In response to these significant negative health and socioeconomic costs, research suggests using new technologies to enhance opportunities for social connectedness as a strategy to help alleviate both social isolation and loneliness. In this context, following a participatory design method, we developed an accessible communication app with and for frail institutionalized older adults. To test the adoption of this innovative technology and its feasibility to address social isolation and loneliness, we conducted a two-month deployment of the app in a long-term care home with five oldest old and their relatives. Due to access, recruitment, and ethical challenges, the oldest old are a specially understudied group. Using an embedded case study (based on interviews, psychometric scales, field observations, and usability and accessibility testing) and a recursive approach to technology studies, our findings show that technology adoption is based on a complex set of interrelated factors: social, attitudinal, physical, digital literacy, and usability. We also discuss the feasibility of the app to enhance perceived social connectedness amongst our target population, provided that at least one strong tie is involved and communication norms and expectations across generations are considered.     

Random projections for Bayesian regression

This article deals with random projections applied as a data reduction technique for Bayesian regression analysis. We show sufficient conditions under which the entire d-dimensional distribution is approximately preserved under random projections by reducing the number of data points from n to \(k\in O({\text {poly}}(d/\varepsilon ))\) in the case \(n\gg d\). Under mild assumptions, we prove that evaluating a Gaussian likelihood function based on the projected data instead of the original data yields a \((1+O(\varepsilon ))\)-approximation in terms of the \(\ell _2\) Wasserstein distance. Our main result shows that the posterior distribution of Bayesian linear regression is approximated up to a small error depending on only an \(\varepsilon \)-fraction of its defining parameters. This holds when using arbitrary Gaussian priors or the degenerate case of uniform distributions over \(\mathbb {R}^d\) for \(\beta \). Our empirical evaluations involve different simulated settings of Bayesian linear regression. Our experiments underline that the proposed method is able to recover the regression model up to small error while considerably reducing the total running time.