From sine-Gordon to vacuumless systems in flat and curved spacetimes

In this work we start from the Higgs prototype model to introduce a new model, which makes a smooth transition between systems with well located minima and systems that support no minima at all. We implement this possibility using the deformation procedure, which allows the obtention of a sine-Gordon-like model, controlled by a real parameter that gives rise to a family of models, reproducing the sine-Gordon and the so-called vacuumless models. We also study the thick brane scenarios associated with these models and investigate their stability and renormalization group flow. In particular, one shows how gravity can change from the 5-dimensional warped geometry with a single extra dimension of infinite extent to the conventional 5-dimensional Minkowski geometry.Comment: 11 pages, 12 figures. Version to appear in EPJ

Earnings Management to Avoid Losses: a cost of debt explanation

In this paper we analyze firms’ earnings management behavior to avoid losses conditional on the (asymmetric) incentive underlying market (positive/negative) returns. Our intuition is that firms with negative returns in the period (bad news, BN) face a higher incentive to undertake earnings management, and that their ultimate intention is to hide from credit markets a signal (loss) that could be translated into a negative impact on their cost of debt. The empirical evidence supports this intuition. BN firms show higher earnings management pervasiveness than their counterparts with good news (GN), and the set with simultaneous BN and prior period positive earnings undertake more pervasive earnings manipulation than BN firms in general. Within this restricted set of firms, and consistent with a cost of debt explanation, we find that firms with larger needs of debt show a higher incidence of earnings management to avoid losses. The overall empirical evidence challenges the implicit assumption in Burgstahler and Dichev (1997) that the incentive to manage earnings is homogeneous to all firms, and suggests that the discontinuities around zero in the earnings distributions are driven, at least partly, by firms’ earnings management behavior.earnings management, earnings thresholds, earnings discontinuities, cost of debt

Piecewise Linear Accrual Models: do they really control for the asymmetric recognition of gains and losses?

The asymmetric recognition of gains and losses underlying conservative accounting is not taken into account by Jones (1991)-type accrual models. Recently, Moreira (2002) and Ball and Shivakumar (2005a) have proposed piecewise linear accrual models designed to control for this asymmetric impact. Our paper first discusses the sign of the expected measurement error in discretionary accruals (DAC) estimates when models do not control for the asymmetry underlying conservatism. We find that DAC in firms with bad news (BN) are expected to be understated, while those in good news (GN) firms will be overstated. Based on this original result we empirically test, using graphical and statistical tools, whether piecewise linear accrual models correct such a measurement error. The empirical evidence shows mixed results. For GN firms the estimates are corrected downwards, as expected; for BN firms, unexpectedly, part of the estimates is also corrected downwards. The reason for this unexpected result seems to lie in a non-linear relationship between accruals and the proxy for BN that the models are unable to control for. Thus, DAC estimates under piecewise linear models are not deemed to be of better quality than those of traditional accrual models.accrual models; piecewise linear accrual models; conservatism; earnings management