An Empirical Study of Credit Default Swaps

We examine the pricing of Asian and non-Asian credit default swaps that traded during the 1997 to 1999 time period. We employ two credit risk models, Duffie and Singleton (1999) and Jarrow and Turnbull (1995). We argue that credit default swaps should have a positive economic value since credit spreads reflect differences in liquidity as well as credit risk. However, in the presence of moral hazard we expect to see negative economic values since asymmetric information would motivate sellers of credit default swaps to demand a “restructuring premium”. While we generally find positive economic values for credit default swaps, both models find negative economic values for Asian credit default swaps during the recent Asian currency crisis, which we attribute to moral hazard.Credit default swaps, moral hazard, recovery rates, asymmetric information

Estimating Corporate Yield Curves

This paper represents the first study of retail deposit spreads of UK financial institutions using stochastic interest rate modelling and the market comparable approach. By replicating quoted fixed deposit rates using the Black Derman and Toy (1990) stochastic interest rate model, we find that the spread between fixed and variable rates of interest can be modeled (and priced) using an interest rate swap analogy. We also find that we can estimate an individual bank deposit yield curve as a spread off a benchmark yield curve. This suggests that we can price a particular bank’s products using arbitrage free interest rate methods since a basic input would be an estimate of the individual bank’s yield curve. Finally, we are able to suggest that the libor/swap is the best benchmark yield curve to estimate an individual bank deposit yield curve.Credit Risk, Yield Curves, Credit Derivatives

Catching Cheats: Detecting Strategic Manipulation in Distributed Optimisation of Electric Vehicle Aggregators

Given the rapid rise of electric vehicles (EVs) worldwide, and the ambitious targets set for the near future, the management of large EV fleets must be seen as a priority. Specifically, we study a scenario where EV charging is managed through self-interested EV aggregators who compete in the day-ahead market in order to purchase the electricity needed to meet their clients' requirements. With the aim of reducing electricity costs and lowering the impact on electricity markets, a centralised bidding coordination framework has been proposed in the literature employing a coordinator. In order to improve privacy and limit the need for the coordinator, we propose a reformulation of the coordination framework as a decentralised algorithm, employing the Alternating Direction Method of Multipliers (ADMM). However, given the self-interested nature of the aggregators, they can deviate from the algorithm in order to reduce their energy costs. Hence, we study the strategic manipulation of the ADMM algorithm and, in doing so, describe and analyse different possible attack vectors and propose a mathematical framework to quantify and detect manipulation. Importantly, this detection framework is not limited the considered EV scenario and can be applied to general ADMM algorithms. Finally, we test the proposed decentralised coordination and manipulation detection algorithms in realistic scenarios using real market and driver data from Spain. Our empirical results show that the decentralised algorithm's convergence to the optimal solution can be effectively disrupted by manipulative attacks achieving convergence to a different non-optimal solution which benefits the attacker. With respect to the detection algorithm, results indicate that it achieves very high accuracies and significantly outperforms a naive benchmark

On modelling credit risk using Arbitrage Free Models

By examining the distribution of state prices obtained from binomial versions of Jarrow and Turnbull (1995), Lando (1998) and Duffie and Singleton (1999), we are able to suggest which credit risk parameters are of critical interest. We find that it appears worthwhile to parameterize credit risk since even the simplest parameterized model obtains large changes in the distribution of state prices when compared to a non-parameterized model. Similarly we find large differences in the distribution of state prices as we add correlation and moderate changes as we add time varying recovery rates. Finally, the choice between the RM or RF recovery assumption appears innocuous, but the choice between RT and these two recovery assumptions is not.Credit risk, credit derivatives, binomial lattice, arbitrage free pricing

Is Rationing in the Microfinance Sector Determined by the Microfinance Type? Evidence from Ghana

This study sets out to examine the extent to which access to credit and credit rationing are influenced by the microfinance type based on the major factors determining micro, small and medium enterprises' access to credit from microfinance institutions in the era of financial liberalization. The data for the study were gleaned from fourteen microfinance institutions' credit and loan records consisting of borrowers and credit characteristics. Our results are puzzling and show that credit rationing is not influenced by the microfinance types but by the individual microfinance institutions

Do Leaders' Characteristics and Regime Transitions in Africa Matter for Citizens' Health Status?

Africa's quest to achieving improved health status and meeting the Millennium Development Goals targets cannot be effectively achieved without examining the quality of leadership, transitions and regimes and how they impact on the decisions and the policy effectiveness that bring about improved health and living standards of the citizenry. In this paper, we study the importance of leader characteristics and regime transitions on government's expenditure in health, and hence on infant mortality, as a development indicator. A unique dataset comprising 44 sub-Saharan African countries spanning from 1970 to 2010 was used for the study. To effectively analyze the impact of leader characteristics and regime transitions on the citizens' health status we control for leader fixed-effects since different leaders, among other things impact on outcomes differently and changes in policy to a large extent depend on the leader characteristics. The overall results are suggestive of a democratic advantage in the process of achieving effective health policy outcomes for promoting health and the wellbeing of the citizens in contemporary sub-Saharan Africa, at least in the long run. Whilst there is evidence of more private and public investments in the health sector under democratic leadership, Government's health policy is virtually non-existent under dictatorships and public sector investment in the health sector is on the decadence

Empowering the Vulnerable to Be Entrepreneurs: An Empirical Test on the Effectiveness of the Ghana Microfinance Policy 2006

The study aims at testing the Ghana Microfinance Policy set up to support the vulnerable through access to credit. We resort to the Blinder-Oaxaca decomposition to determine if there is positive discrimination in favor of women and young entrepreneurs in the rationing behavior of the microfinance companies. This is what we should expect if the policy is effective. Our results show that even after controlling for a large number of borrower characteristics, microfinance type and credit worthiness variables, there is positive discrimination that favors female and young entrepreneurs as this discrimination is largely determined by the differential treatment these groups receive in respect of men and older borrowers from microfinance institutions. Our results show that the Government microfinance is the most severe in the rationing behavior towards the discriminating groups