Economic Indicators

Auto and Truck Sales
Importance (A-F): This release merits a C-.
Source: Individual auto manufacturers, seasonal factors by the Commerce Department.
Release Time: Varies by auto maker from the first business day to the third business day of the month (data for month prior).
In Brief
Auto and Truck Sales measure the monthly sales of all domestically produced vehicles. They are considered an important indicator of consumer demand, accounting for roughly 25% of total retail sales. Demand for big ticket items such as autos and trucks tends to be interest rate sensitive, making the motor vehicle sector a leading indicator of business cycles.
Each auto maker reports sales individually. The reports are typically released over the course of the first three business days of the month. Using the individual reports, a total annual sales pace can be calculated after applying Commerce Department seasonal factors. It is this annual sales pace that the market refers to when discussing auto and truck sales for the month.In Depth
Vehicle sales figures rarely grab the attention of the market probably for two reasons. First, though the specifics of the data are not terribly difficult to understand, their implications are a little hard to trace. Second, unlike many economic releases, vehicle sales are not released all at once and at the same time every month. This makes it difficult for the market to quickly interpret what the numbers mean for the overall consumption picture and to react accordingly.
This is what happens in terms of vehicle sales during the course of any given month:
The individual vehicle manufacturers report their sales results during the first three or four days of the month.
A day after the last manufacturer reports the Bureau of Economic Analysis releases its estimate of unit auto sales.
About a week after that the BEA releases its estimate of unit truck sales.
The Census Bureau releases its retail sales report, including a measure of sales at automotive dealers, usually around the 13th of the month.
Roughly two weeks after that the BEA releases its personal income and outlays release, including a measure of spending on motor vehicles and parts.
Each item in this list warrants a more detailed discussion.
ManufacturersMost vehicle manufacturers usually always report sales results on the first business day of the month; Ford does not report until the third business day. As these individual results trickle out over the news wires throughout the day, diligent economists and market analysts are busy calculating running totals and applying seasonal factors to them--the BEA supplies factors for the coming six months in advance--in order to come up with approximations for auto and truck sales rates. These figures are some of the first hard spending data for any given month; comparing these derived rates to those from months and years prior is a big help when it comes to formulating a consumption forecast for the month.
Unit SalesOnce economists and analysts have translated individual sales results into annual rates, they turn to the BEA to provide "official" unit sales rates. Unfortunately, though the BEA is using the same seasonal factors as the rest of us, more often than not it produces unit rates that are modestly different than the ones that market previously had in mind. Thankfully, however, these differences usually pop up in the individual sales categories--domestic car sales, import car sales, domestic truck sales, and import truck sales--but wash out when all the vehicle types are aggregated.
Retail SalesWith unit sales rates in hand we can proceed to forecast the auto sales contribution to the retail sales figure. And this link is important. In fact, autos often prove to be such a significant swing factor that retail sales are scrutinised on both a total and an excluding-autos basis. It is also worth remembering that the auto term in the retail report is notoriously difficult to estimate; it is not at all rare to see it decline (increase) during a month when unit auto sales rise (fall). Still, by the time the retail sales report rolls around, a few other preliminary spending gauges can be used in conjunction with the unit auto data to get a pretty good read on whether retail consumption rose or fell for the month.
Personal Consumption ExpenditureWith unit sales rates and retail auto spending data in hand analysts can hone their estimates for the auto category in the personal consumption release. Many analysts place relatively more emphasis on the retail auto figures to sharpen their PCE estimates, but the unit auto numbers typically have better predictive power for that series. Besides, it is not commonly known that the BEA does not rely at all on the the retail sales data to produce its consumption estimates. Thus, as an important component of the monthly consumption figures that go directly into the quarterly GDP calculation, the PCE auto data are most important to economic forecasters.