The relationships of alternative energies with the technology sector and non-renewable energies

Este trabalho tem como objectivo compreender de que forma os investidores veem as energias renováveis: se as veem como parte do sector tecnológico, à espera de novos desenvolvimentos, ou como uma alternativa aos métodos existentes de produção de energia. Para responder a esta questão, foi desenvolvido um modelo de vectores autoregressivos com quatro variáveis de forma a se poder aplicar um Granger causality test e Impulse Response function. Os resultados sugerem que para o período de 2002-2007 à escala global ambas as hipóteses se confirmam, porém de 2009-2014 os resultados sugerem que os investidores não reconhecem as energias renováveis como um ramo do sector tecnológico, neste período. Para além disso, durante o período de 2009-2014, e quando comparados investidores Americanos com Europeus, os resultados sugerem que apenas o último identifica as energias renováveis como uma fonte viável para a produção energética.

Cash-cum-in-kind transfers and income tax function

This paper investigates income tax revenues response to tax rate changes taking into consideration that cash-cum-in-kind transfers are used as a redistributive package to the community. First, we show that when cash and in-kind transfers are not tied to be substitute instruments, a marginal income tax increase may unambiguously decrease the quantity supplied of labor (and tax revenues therein). Next, we show that whenever the government chooses the optimum provision for the publicly provided good the tax revenue function has a negatively-sloped part with respect to tax rates except for one case. Last, we consider Brazilian data - PNAD - from 1976 to 2008 to test our theoretical implications. Our estimations suggest a weak evidence in favor of the existence of a La er-type curve for Brazilian income tax revenues data. Moreover, wend that the actual average income tax rate seems to be below the estimated optimum level. In a shorter sample from 1996-1999, we nd evidence that labor supply decreases with tax rate when cash and in-kind transfers are in play. Using a pseudo-panel from the same shorter sample, we try to estimate the elasticity of taxable income, following Creedy and Gemmell (2012) and Saez et al. (2009). We explore a small tax reform between 1997 and 1998 that a ected only the higher income tax bracket, and evidence that Brazil is on the revenue reducing side of the La er Curve, at least for individuals in the higher income tax bracket.