**Graph of the Week**, and kindly contributed to R-bloggers)

**Description:**

Yearly average airline fare since 1995.

**Data:**

**Analysis:**

When taking the average price of domestic airline fares, there is a clear trend indicating that flying is becoming more affordable – when adjusted for inflation. This may seem impossible when you look at the current price of your ticket and see that it is higher than last year. That’s because the last two years have seen an increase, but the overall trend is still downward.

How can the airlines sustain this downward price trend with the cost of fuel going up? In an earlier article, it was shown that gas isn’t as expensive as it appears – again, when adjusted for inflation. That being said, gas prices have increased in the last couple of years, which may explain the air fare prices going up in the same period.

According to the Bureau of Transportation Statistics (BTS), baggage fees have gone up each year since they have been tracked (since 2007); perhaps this has also kept airline fees in check. When you calculate the total baggage fees collected for a flight and divide that by the number of passengers, you get the average baggage fee per passenger. That table looks like this:

__Average Baggage Fee:__

2007 – $0.60 / passenger

2008 – $1.53 / passenger

2009 – $3.85 / passenger

2010 – $4.67 / passenger

2011 – $4.61 / passenger (only through 3 quarters – BTS doesn’t have 4Q 2011 as March 2012)

If you add the average baggage fee to the average airline fee, then the total cost to fly only goes up by less than $5 in all cases. Thus, the downward trend in ticket prices would still continue.

Maybe this * is *affecting the airlines since their population appears to be dwindling (mostly due to mergers):

__Active Airline Carriers__:

2007 – 22

2008 – 21

2009 – 22

2010 – 20

2011 – 17

Whether or not this has anything to do with reduced fares is open for speculation and warrants an investigation in its own right. That being said, the upward trend of ticket prices in the last 2 years corresponds with the drop in carriers during that same time. This will be something to monitor as time progresses.

Another point to consider is the cost of meals and drinks on airlines. In the past these were complimentary, but now a passenger must pay for anything beyond the typical “bag of peanuts.” Undoubtedly this has saved airlines millions of dollars and thus enabled them to keep their prices competitive.

One can only hope that the fares remain stable so that we can all afford to fly for the foreseeable future.

**Questions:**

1) Will more fuel-efficient planes help to reduce ticket prices?

2) What are the barriers for low-cost airlines to enter the market?

3) Is there an alternative fuel solution for large planes?

**Code:**

This graph was generated using the ‘ggplot2‘ package within the R programming language:

ggplot(adjusted.airfare.frame, aes(ymin=250, x=Year, y=Average_Fare)) + geom_line(size=1.1) + geom_point() + geom_smooth(size=1.1, method="lm", na.rm=FALSE) + ylab("Average Fare (in U.S. Dollars)") + xlab("Year") + opts(title="Airline Average Fare (adjusted for inflation)", panel.background = theme_blank(), plot.margin = unit(c(0,4,0,0), "lines"))

**Further Reading (the following all have at least 3 stars or are unrated):**

**leave a comment**for the author, please follow the link and comment on their blog:

**Graph of the Week**.

R-bloggers.com offers

**daily e-mail updates**about R news and tutorials on topics such as: visualization (ggplot2, Boxplots, maps, animation), programming (RStudio, Sweave, LaTeX, SQL, Eclipse, git, hadoop, Web Scraping) statistics (regression, PCA, time series, trading) and more...