Do ski resorts fudge the data?

Don’t al­ways be­lieve what the ski re­sorts tell you.
Two Dart­mouth eco­nom­ics pro­fes­sors have found that ski re­sorts tend to ex­ag­ger­ate their re­ported snow­fall, es­pe­cially on week­ends. The pro­fes­sors pre­sented their study at a Na­tional Bu­reau of Eco­nomic Re­search con­fer­ence over the sum­mer.
The study's au­thors, Jonathan Zin­man and Eric Zitze­witz, found that ski re­sorts re­port 23 per­cent more snow­fall on week­ends, which, ac­cord­ing to their analy­sis, does not cor­re­late with gov­ern­ment pre­cip­i­ta­tion data.
Ski re­sorts that "reap greater ben­e­fits" from in­creased snow re­ports tend to ex­ag­ger­ate more fre­quently, Zin­man and Zitze­witz found. Re­sorts that have a large pop­u­la­tion within dri­ving dis­tance, for ex­am­ple, ex­hib­ited a greater “week­end ef­fect,” ac­cord­ing to the re­port.
Parker Riehle, pres­i­dent of the Ver­mont Ski Area As­so­ci­a­tion, told Ver­mont Pub­lic Radio that the study com­pares data from dif­fer­ent el­e­va­tions, lead­ing to un­fair con­clu­sions.
Zitze­witz, how­ever, said in an in­ter­view with The Dart­mouth that the week­end ef­fect the study cap­tures can­not be at­trib­uted to a con­sis­tent dis­crep­ancy in the data.
He also said that the weather sta­tions used for com­par­i­son in the study were close to the cor­re­spond­ing ski re­sorts both in terms of el­e­va­tion and hor­i­zon­tal dis­tance.
"We were very care­ful to match re­sorts with weather sta­tions that aren't very far away," he said.
The re­port also ex­am­ines the ef­fect of a new iPhone ap­pli­ca­tion on re­sort snow­fall re­ports. The ap­pli­ca­tion, re­leased on Jan. 8 by SkiReport.​com, al­lows users to com­ment on ski con­di­tions. Users’ posts ap­pear below the re­ported snow­fall on Ski Re­port’s web site.
Usage of the ap­pli­ca­tion "in­creased dra­mat­i­cally fol­low­ing the fea­ture launch," ac­cord­ing to the study, and led to a sharp de­cline in the mea­sured week­end ef­fect.
The de­cline, how­ever, was only ev­i­dent at ski re­sorts that have ad­e­quate data cov­er­age to allow for iPhone use.
Zitze­witz said he and Zin­man chose to in­ves­ti­gate the issue be­cause it of­fered the abil­ity to look at ad­ver­tised qual­ity and "ob­serve ob­jec­tively what the true qual­ity was.”
"The aca­d­e­m­i­cally in­ter­est­ing thing about this study is it's an op­por­tu­nity to study de­cep­tive ad­ver­tis­ing em­pir­i­cally," he said.