Markowitz optimization, a key component of modern portfolio theory, is prone to estimation errors in mean vector and covariance matrix, leading to unrealistic portfolio weights, limited diversification, and weak out-of-sample performance. In response, a heuristic portfolio resampling approach...

Markowitz optimization plays an important role in modern portfolio theory. However, it is well-known that Markowitz optimization is highly affected by the estimation error of the mean vector and covariance matrix, resulting in extreme and/or unrealistic portfolio weights, lacks of...

Usually, inflation is optimally forecasted using simple time series models or a Phillips' curve process. However, as more people become online shoppers, ``online inflation'' turns out to be a good predictor of official inflation too. Online prices can be obtained at a higher frequency than...

In this paper, we address whether using a disaggregated series or combining an aggregated and disaggregated series improves the forecasting of the aggregated series compared to using the aggregated series alone. We used econometric techniques, such as the weighted lag adaptive least absolute...

We test forecast rationality for Brazilian inflation using Survey of Professional Forecasters (SPF) for each month. We consider panel data traditional tests as Mincer and Zarnowitz (1969) and West and McCracken (1998) to verify if forecast errors have zero mean and are uncorrelated with the...

General dynamic factor models have demonstrated their capacity to circumvent the curse of dimensionality in the analysis of high-dimensional time series and have been successfully considered in many economic and financial applications. Being second-order models, however, they are sensitive to...

Based on a General Dynamic Factor Model with infinite-dimensional factor space and MGARCH common shocks, we develop new estimation and forecasting procedures for conditional covariance matrices in high-dimensional time series. The finite-sample performance of our approach is evaluated via Monte...