The following two plots on the next page show exponentially weighted moving averages of the percentage change in the amount of household credit market debt. The time series is quarterly, from 1960...

The following two plots on the next page show exponentially weighted moving averages of the percentage change in the amount of household credit market debt. The time series is quarterly, from 1960 through the fourth quarter of 2011. In the first plot the weight for the EWMA
, whereas in the second plot
. The EWMA in both cases is shown as a red line with the surrounding data. (The Federal Reserve Bank of St. Louis provides these data online.)

(a) Which weight
 do you think produces a better summary of the underlying trend in the percentage change in household debt? Explain your choice.

(b) In the fourth quarter of 2011, household credit debt was estimated to be
13.223 trillion. Having seen these plots, forecast household credit debit in the first quarter of 2012.

(c) Provide a range to accompany your forecast of household credit debt.