Dr. Singh as an economist.

No doubt he was most learned political leader. As an economist he handled several issues in his tenure. 1. Financial crisis (Reason : high fiscal deficit, subsidy burden, gulf war leading to low remittances, collapse of USSR who gave financial aid) 2. Economic reforms : This may sound as an easy task, opening the economy to foreign investment, but this is easier said than done. Domestic companies capacity, protecting sensitive sectors, sectoral policy revision and augmenting capacity to tackle workload, preventing economic power concentration are just few factors to be considered. 3. Post 2000s FDI surge : managing the liquidity in market, controlling rupee appreciation because of that. 4. Handling 2008 Financial Crisis : he didn't open sensitive sectors to FPI and FDI so crisis impact was dampened. But construction sector and investment did face the heat. Rupee fell hard. Fiscal package boost gave major relief. 5. Package of social sector program : MGNREGA 2006 , RTE 2009, RTI 2005, NFSA 2014. All legal entitlement. 6. Another financial crisis 2013 (eurozone crisis) : similar impact as 2008 event. These are just economic things that he handled. However, politics did him bad. He couldn't go too far because of political compulsions like restructuring of PSUs. You guys can add too if u remember anything like this. (i might be wrong, open to corrections)