Explanation:

 The twin balance sheet challenge is the major impediment to private investment and a full-fledged economic recovery. To address the challenges, Economic Survey recommends these four R's: Recognition, Recapitalization, Resolution, and Reform.

Banks must value their assets as far as possible close to true value (recognition) as the RBI has been emphasizing; once they do so, their capital position must be safeguarded via infusions of equity (re-capitalisation) as the banks have been demanding, said the survey.

The underlying stressed assets in the corporate sector must be sold or rehabilitated (resolution) as the government has been desiring, and future incentives for the Private Sector and corporates must be set-right (reform) to avoid a repetition of the problem