Forecasting the AR(1) Time Series Model ˆβ1=∑i=1(xi−ˉx)(yi−ˉy)√∑ni=1(xi−ˉx)∑ni=1(yi−ˉy). In the AR(1) model we may set yt−1=zt,t=2,…,T, xt=zt,t=1,…,T−1 and n=T−1 and plug-in the above formula to obtain an efficient estimate of β1.
The pro forma accounts receivable (A/R) balance can be determined by rearranging the formula from earlier. The forecasted accounts receivable balance is equal to the days sales outstanding (DSO) assumption divided by 365 days, multiplied by 365 days.
Here's a common formula for forecasting sales: Sales Forecast = (Last Month Revenue + Expected Growth – Expected Churn) DSO = (Accounts Receivable / Total Credit Sales) x Number of Days in the Period. Accounts Receivable Forecast = Days Sales Outstanding (DSO) x (Sales Forecast / Time)
The AR balance is based on the average number of days in which revenue will be received. Revenue in each period is multiplied by the turnover days and divided by the number of days in the period to arrive at the AR balance.
The pro forma accounts receivable (A/R) balance can be determined by rearranging the formula from earlier. The forecasted accounts receivable balance is equal to the days sales outstanding (DSO) assumption divided by 365 days, multiplied by 365 days.
By dividing DSO by 365 (the total number of days per year), you get a daily rate of how long it typically takes to collect a receivable. Multiplying this rate by your sales forecast gives you an estimated accounts receivable amount you can expect for that period.
You can find the AR aging percentage by dividing the total amount of receivables that are over 90 days past due by the total amount of receivables outstanding.