Combining the minimum-variance and equally-weighted portfolios: Can portfolio performance be improved?

It is documented in the literature that due to estimation errors, mean-variance efficient portfolios deliver no higher out-of-sample Sharpe ratios than does the naïve equally-weighted portfolio (EWP). This paper demonstrates how the out-of-sample performance of the minimum-variance portfolio (MVP) can be improved in the presence of estimation errors by combining the MVP and EWP. Our results indicate that an appropriate combination of the MVP and EWP can enhance Sharpe ratios under any scenarios considered, and can also reduce the portfolio risk if short-selling is allowed. However, the combination strategy is not able to generate a lower risk level than the MVP when a short-selling restriction is imposed. We find that the optimal combination coefficient depends on the factors that greatly impact estimation errors in the MVP, including sample size, estimation method, no-short-selling restriction, and length of the out-of-sample period under consideration.     

Inflation and relative price variability: Evidence for India

This study decomposes relative price variability into a component due to inflation and a component due to real factors. The empirical results for India suggest that real factors account for 55% and inflation accounts for 45% of the variability in relative price changes. The proportion of inflation induced relative price variability increases with the rise in inflation, implying that inflation has distortionary effects on the structure of relative prices. Further, larger part of variability in the relative price changes seems to have been generated by fluctuations in the relative prices of a few commodities. The sector wise analysis shows that the major share of total relative price variability is contributed by fluctuations in the prices of manufactured products. The more crucial inference that emerges from the empirical analysis is that the inflation rate at which variability of relative price changes is minimum is found to be 4.5%, which is consistent with the official threshold rate often claimed by the Reserve Bank of India.