Optimal financial contracting and debt maturity structure under adverse selection

We analyze a model in which a risk-averse country finances its development project under asymmetric information. Before the project renders its fruits, two types of news will become available, one of which will reduce the asymmetry of information between the country and its investors. We characterize the optimal financial contract both when complete financial contracting is possible and when the country is restricted to using only short-term and long-term debt.

Signaling Credibility --- Choosing Optimal Debt and International Reserves

This paper evaluates the challenges facing developing countries when there is uncertainty about the policy maker type. We consider a country characterized by volatile output, inelastic demand for fiscal outlays, high tax collection costs, and sovereign risk, where future output depends on the type of policymaker in place today. There are two policymakers -- type T chooses debt and international reserves to smooth tax collection costs; type S has higher discount factor, aiming at obtaining current resources for narrow interest groups, and preferring not to undertake costly reforms that may enhance future output. Financial markets do not know the type of policymaker in place and try to infer its type by looking at its financial choices. We show that various adverse shocks (lower output, higher real interest rate, etc.) can induce a switch from an equilibrium where each policy maker chooses its preferred policy to another where T distorts its policies in order to separate itself from S in the least costly way. This is accomplished by type T reducing both international reserves and external debt. Further decline in output would induce type T to lower debt, and reserves would fall at a higher rate than otherwise expected.

Comment on Singularity-free Cosmological Solutions with Non-rotating Perfect Fluids

A conjecture stated by Raychaudhuri which claims that the only physical perfect fluid non-rotating non-singular cosmological models are comprised in the Ruiz-Senovilla and Fernandez-Jambrina families is shown to be incorrect. An explicit counterexample is provided and the failure of the argument leading to the result is explicitly pointed out.Comment: LaTeX, 5 page

A proposal of a Renormalization Group transformation

We propose a family of renormalization group transformations characterized by free parameters that may be tuned in order to reduce the truncation effects. As a check we test them in the three dimensional XY model. The Schwinger--Dyson equations are used to study the renormalization group flow.Comment: Contribution to Lattice'94. uuencoded postscript fil

Automating SLA-Driven API Development with SLA4OAI

The OpenAPI Specification (OAS) is the de facto standard to describe RESTful APIs from a functional perspective. OAS has been a success due to its simple model and the wide ecosystem of tools supporting the SLA-Driven API development lifecycle. Unfortunately, the current OAS scope ignores crucial information for an API such as its Service Level Agreement (SLA). Therefore, in terms of description and management of non-functional information, the disadvantages of not having a standard include the vendor lock-in and prevent the ecosystem to grow and handle extra functional aspects. In this paper, we present SLA4OAI, pioneering in extending OAS not only allowing the specification of SLAs, but also supporting some stages of the SLA-Driven API lifecycle with an open-source ecosystem. Finally, we validate our proposal having modeled 5488 limitations in 148 plans of 35 real-world APIs and show an initial interest from the industry with 600 and 1900 downloads and installs of the SLA Instrumentation Library and the SLA Engine.Ministerio de Economía y Competitividad TIN2015-70560-RMinisterio de Ciencia, Innovación y Universidades RTI2018-101204-B-C21Ministerio de Educación, Cultura y Deporte FPU15/0298

Fostering SLA-Driven API Specifications

Software architecture tendencies are shifting to a microservice paradigm. In this context, RESTful APIs are being established the standard of integration. API designer often identifies two key issues to be competitive in such growing market. On the one hand, the generation of accurate documentation of the behavior and capabilities of the API to promote its usage; on the other hand, the design of a pricing plan that fits into the potential API user’s needs. Besides the increasing number of API modeling alternatives is emerging, there is a lack of proposals on the definition of flexible pricing plans usually contained in the Service Level Agreements (SLAs). In this paper we propose two different modeling techniques for the description of SLA in a RESTful API context: iAgree and SLA4OAI.Ministerio de Economía y Competitividad TIN2015-70560-RJunta de Andalucía P12-TIC-1867Ministerio de Economía y Competitividad TIN2014-53986-RED

Tax Reforms in an Endogenous Growth Model with Pollution

This paper discusses the effects of a green tax reform in an AK growth model without abatement activities and with a negative environmental externality in utility function. There is also a non-optimal level of public spending. The results depend on the financing source of public spending. When there is not public debt, a revenue-neutral green tax reform has not any effect on pollution, growth and welfare. On the contrary, when short-run deficits are financed by debt issuing, a variety of green tax reforms increase welfare. Nevertheless, in this framework, non-green tax reforms are also welfare improving.Environmental externalities, Economic growth, Pollution taxes, Laffer Curve.

Environmental fiscal policies might be ineffective to control pollution

In a one sector growth model with pollution in the utility function, the competitive equilibrium can be indeterminate for plausible values of the intertemporal substitution elasticity of consumption and under constant returns to scale. The tax rate on pollution does not enter the condition characterizing indeterminacy. This means that the government is not able to control emissions in the economy by using environmental policies. Non-separability between private consumption and pollution in the utility function is crucial for this result.Indeterminacy, Environmental taxes, Pollution