Непараметрический метод оболочечного анализа для портфельных построений на российском рынке облигаций
In this paper for the first time on the base of the non-parametric Data Envelopment Analysis (DEA) method the authors build and test portfolios in the Russian bond market. Using DEA we perform integral evaluation and rank by optimality (efficiency) outstanding ruble corporate bonds from the perspective of a private investor. Our original algorithm for building an optimal bond portfolio includes two analytical procedures: first we identify the determinants of the yield to maturity of ruble corporate bonds for a diversified sample of real sector companies from 2008 to 2015, then we apply the DEA method for this sample in order to find the optimal set of bonds for the portfolio. At the final stage we test (for 2014—2015) an investment strategy based on picking for the portfolio the ruble corporate bonds that reached the efficiency frontier. In order to identify the determinants of ruble corporate bond yields we analyze a set of macroeconomic and firm-level (financial and non-fundamental) factors, characteristics of bond issues using econometric methods. For the first time in the Russian bond market we consider not only current but also expected inflation and GDP growth, risk indicators (the volatility index RTS VIX as a proxy). We identify the optimal bond issues (the bond issues that reached the efficiency frontier) taking into account a set of different factors: yield to maturity, duration and liquidity of bond issues, credit risk indicators of bond issuers. The results of a regression analysis confirm our hypothesis that yield to maturity is significantly influenced by revenue of a bond issuer, the repo eligible factor (inclusion of a bond issue in the Lombard list of the Bank of Russia), the government’s share in the equity, the bond issuer’s debt burden indicators, the level of current and expected inflation. The efficiency (optimality) frontier mainly consists of bond issues of large companies with the government’s participation in the equity. Our hypothesis that investing in the bond issues on the efficiency frontier can beat the bond benchmarks’ returns and “return / volatility” ratios are confirmed in part, for the period of 2014 characterized by a decrease in prices of ruble bonds.