Hi Experts, I have daily returns data for firms. I would like to calculate the standard deviation of the returns (say, sigma) from the daily observations for the last 3 months on a rolling basis. For example, sigma for for firm i in december 2017 will be the standard deviations of the daily returns from september to november 2017. Similarly, sigma for firm i in november 2017 will be the standard deviations of the daily returns from august to october 2017. Thanks, Abu   ... View more

Hi Experts, I use the following code to insert a blank row for each observation:   data want; set have; output; /* Output real observation */ if mod(_n_,1)=0; array allnums {*} _numeric_ ; array allchar {*} _character_ ; drop i; do i=1 to dim(allnums); allnums{i}=.; end; do i=1 to dim(allchar); allchar{i}=' '; end; output; /* Output blank observation */ run; options missing=' '; /* Display numeric missing as blank */     My question is: How can I insert two or more blank rows for each observation? Another question is: How can I insert a blank row in the beginning of the dataset?   Thanks, Abu Chowdhury ... View more