Forecasting accuracy and estimation uncertainty using VAR models with short- and long-term economic restrictions: a Monte-Carlo study

Using vector autoregressive (VAR) models and Monte-Carlo simulation methods we investigate the potential gains for forecasting accuracy and estimation uncertainty of two commonly used restrictions arising from economic relationships. The Örst reduces parameter space by imposing long-term restrictions on the behavior of economic variables as discussed by the literature on cointegration, and the second reduces parameter space by imposing short-term restrictions as discussed by the literature on serial-correlation common features (SCCF). Our simulations cover three important issues on model building, estimation, and forecasting. First, we examine the performance of standard and modiÖed information criteria in choosing lag length for cointegrated VARs with SCCF restrictions. Second, we provide a comparison of forecasting accuracy of Ötted VARs when only cointegration restrictions are imposed and when cointegration and SCCF restrictions are jointly imposed. Third, we propose a new estimation algorithm where short- and long-term restrictions interact to estimate the cointegrating and the cofeature spaces respectively. We have three basic results. First, ignoring SCCF restrictions has a high cost in terms of model selection, because standard information criteria chooses too frequently inconsistent models, with too small a lag length. Criteria selecting lag and rank simultaneously have a superior performance in this case. Second, this translates into a superior forecasting performance of the restricted VECM over the VECM, with important improvements in forecasting accuracy ñreaching more than 100% in extreme cases. Third, the new algorithm proposed here fares very well in terms of parameter estimation, even when we consider the estimation of long-term parameters, opening up the discussion of joint estimation of short- and long-term parameters in VAR models.

Robustness and stabilization properties of monetary policy rules in Brazil

Based on three versions of a small macroeconomic model for Brazil, this paper presents empirical evidence on the effects of parameter uncertainty on monetary policy rules and on the robustness of optimal and simple rules over different model specifications. By comparing the optimal policy rule under parameter uncertainty with the rule calculated under purely additive uncertainty, we find that parameter uncertainty should make policymakers react less aggressively to the economy's state variables, as suggested by Brainard's "conservatism principIe", although this effect seems to be relatively small. We then informally investigate each rule's robustness by analyzing the performance of policy rules derived from each model under each one of the alternative models. We find that optimal rules derived from each model perform very poorly under alternative models, whereas a simple Taylor rule is relatively robusto We also fmd that even within a specific model, the Taylor rule may perform better than the optimal rule under particularly unfavorable realizations from the policymaker' s loss distribution function.

Growth process in business and social entrepreneurship: the case of Brazil

The purpose of the dissertation is to investigate in depth the difference between the challenges social and business entrepreneurs face in the growth phase of their business in the particular environment of Brazil. This objective has been achieved through a two-steps methodology. The first step is a set of in-depth interviews carried out with industry experts such as professors, venture capitalists, consultants, fund managers or people involved in the support of growing startups (i.e. accelerators). These interviews allowed, first, to build a general perspective on the environment entrepreneurs operate into and to identify a list of challenges entrepreneurs face in the growth process of their business. This list was completed with the additional challenges identified in the previous literature. The second step of the methodology was to test the relevance of these challenges in the mind and experience of social and traditional entrepreneurs. A questionnaire was then submitted to 145 social and 286 traditional entrepreneurs. The results were statistically analyzed to test the relative relevance of these challenges for one group of entrepreneurs with respect to the other. The outcome of the analysis was significant. The most relevant challenges identified were, for both groups, taxation, bureaucracy, finding the right employees, creating effective teams, measuring firm performance and social value creation and obtaining funds. On the other side motivation, innovation, competition and lack of market space for growth represented the least relevant issues in the minds of entrepreneurs. This rank however did not differ significantly from social to traditional entrepreneurs. This testifies that in Brazil social and traditional entrepreneurs face the same set of challenges despite the widespread belief of the opposite.