Whenever friends back home in Chile rile against U.S. consumerism, shallowness or corporate greed, I often find myself defending this country. My favorite counterargument: Thanksgiving.

As an international student, Thanksgiving has always struck me as the “purest” of holidays. No other country (except Canada) has an entire national holiday entirely dedicated to simply having dinner with family or friends. There is no explicit religion behind it, no gift-giving or -receiving. Anyone can celebrate Thanksgiving, from the WASP-iest family to the most recent immigrants. Time with those you love is the sole point of the holiday. People spend the day at home, cook together, share a delicious meal, watch football (alas, not soccer) and give thanks for the good things in their lives. Families that are spread out over North America fly hundreds of miles just to be with each other. Christmas Eve dinner is similar, but with two months of anticipation, massive retail consumption and religious origins — it does not reach the same degree of distilled family joy.

But there is a “black” cloud looming over this American wonder. As you know, the day after Thanksgiving is the beginning of the Christmas shopping season, marked by the largest retail discounts of the year. This day in principle is good — the shopping season has to start at some point, and Black Friday has been a thing since at least the 1960s.

In the past five years or so, though, it has steadily encroached upon Thanksgiving. Last year, for the first time, many large department stores opened before midnight. This year Wal-Mart opened at 8 p.m. My stomach churned when I first read about this, as I imagined tens of millions of Americans cutting short their Thanksgiving dinners, with turkeys left warm on the table, to save $150 on a flat-screen TV or a new grill. Thousands lined up outside retailers throughout Thanksgiving Day, possibly forgoing dinner altogether.

According to the National Retail Federation, the number of Black Friday shoppers rose from 140 million in 2006 to 226 million in 2011. I shudder thinking how many of those millions began their shopping on Thursday this year, and how much earlier it will begin next year. I was shocked by the lack of controversy this massive shift in consumer behavior has caused. There were columns in major papers last year, but very few this year. The country is getting used to this new “Black Thursday.”

Some may wonder why this is a problem. If people want to shop, why shouldn’t they? Who am I to say they are wrong in wanting to shop, or to blame retail stores for simply meeting their demands? After all, Wal-Mart says it opened at 8 p.m. this Thanksgiving in response to consumer feedback.

Besides the fact that hundreds of thousands of retail employees are unable to enjoy a federal holiday (which has led to strikes in some Wal-Marts), encroachment on Thanksgiving is a market failure and erodes social welfare. Yes, increased consumption strengthens the economy, and Black Friday is rightfully seen as a bellwether of consumer confidence. But the economy is ultimately about what we value. Gross domestic product increases because we sell, produce and earn more, and we only sell or produce things people value. I’m certain that people value time spent with their families on Thanksgiving, but this non-monetary value is not shown in GDP. Black Thursday savings may offset this value for many families in tough economic times.

Opening this early, though, is not Pareto efficient. If Thanksgiving were shielded by a ban on Thursday retail openings, people (and the economy) would still get the value of Black Friday shopping on Friday, while getting all of the value of Thanksgiving on Thursday. Big shopping sales can fall on any day, so having them begin on Friday instead of Thursday makes little difference, but Thanksgiving only happens on Thanksgiving. Families value Thanksgiving, retailers do not — this market failure requires correction.

America, please protect the Thanksgiving tradition. I don’t think you realize how unique it is. For one day, let family trump materialism. Please don’t prove me wrong when I defend you back home.

Diego Salvatierra is a senior in Pierson College. Contact him at diego.salvatierra@yale.edu .