If you were surprised by the news that U.S. citizens will need passports to re-enter the country after visiting border cities like Tijuana even for a few hours, you’re in good company. So was President Bush. His reaction after reading about it in a newspaper: “What’s going on here? I think it’s going to disrupt honest flow of traffic.”

Well, it was Bush’s signature that created the Intelligence Reform and Terrorism Prevention Act of 2004, which mandated that the secretary of homeland security, in consultation with the secretary of state, “develop and implement a plan to require U.S. citizens and foreign nationals to present a passport or other secure document when entering the United States.” This in turn created the Western Hemisphere Travel Initiative.

The problem under the new law is not about entering Mexico — it’s about getting back into the United States. Historically, U.S. citizens typically undergo only visual and linguistic profiling by border inspectors. The need to show even a driver’s license is often not required.

Any time a new condition is imposed on border crossers, crossing delays, at least for a time, follow. But the big fear is that its imposition will cause the cancellation of crossing trips altogether by San Diegans and others. About 20 percent of Americans (around 60 million) have passports or other formal proof of citizenship.

Americans associate a passport with foreign travel. Since most of us don’t travel outside of North America, there has never been a need to spend the time and money obtaining one. People without passports are likely to forgo trips into Tijuana, hurting its economy.

As a group, high school and college students crossing the border spend a lot of money. If they are 18 or older, they can obtain a passport, but will they spend $97 and wait the month or so it takes to arrive?

Possibly a military ID card could qualify in lieu of a passport. The Navy and Marine regional commands, however, may petition the Department of Homeland Security not to include these cards as qualifying alternatives, to discourage young service members from crossing the border.

Although the new law has less effect on Mexican nationals crossing into San Diego, the repercussions of reduced U.S. tourism dollars in Baja could set off a chain reaction affecting both Baja and San Diego. Fewer tourist dollars affect San Diego distributors of goods and services to Baja’s hotel and food and beverage industries. Less tourism negates the need for investing in more hotels, restaurants, and stores catering to visitors.

Much of the material and equipment for construction is either rented or purchased from the San Diego region, as is the wood and much of the components in the furniture manufacturing industry that sells to hotels and restaurants. Visitors’ gratuities make tourist-related wages among the highest for blue-collar workers who in turn cross to San Diego to visit and purchase goods. Less tourism means less spendable income and less employment in those industries.

Each of these circumstances sets off its own chain reaction beyond the immediate industries. In San Diego, the border economy is worth $14 billion, about 10 percent of the gross regional product. Tijuana’s gross regional product hovers around $5 billion so the potential for economic disruption is great.

Further problems are presented to the market that caters to the day or occasional weekend visits to Tijuana and places like Rosarito Beach and Ensenada. Will individuals and families be motivated to obtain passports and go through the expense? For a family, the cost of acquiring the 10-year passports could be several hundred dollars. It almost certainly will act as a travel deterrent to lower-income families.

In the San Diego region, some other forms of proof of citizenship will be accepted, such as the SENTRI (Secure Electronic Network for Travelers Rapid Inspection) cards held by those who use dedicated commuter lanes, both vehicular and pedestrian, to expedite daily travel across the border. Enrollment in the program is $120 per person for a pass good for two years. The program also is more expensive and requires a thorough investigation of applicants. But the number of cardholders is relatively small.

The Department of Homeland Security’s border crossing data shows how busy the ports of entry at San Ysidro, Otay Mesa and Tecate are. Each day, 136,000 passenger vehicles and 355,000 individuals cross both ways. Annually, those figures total 49.6 million and 129.6 million.

The San Diego Association of Governments study, “Estimating the Economic Impacts of Border Wait Times at the San Diego-Baja California Border Region,” provides a glimpse of the binational region’s economic integration and size.

Preliminary surveys of passengers in vehicles and pedestrians waiting to enter the United States indicate that 29.3 percent live in the United States and 70.7 percent live in Mexico. Using the Homeland Security data, these percentages translate into 104,915 daily border crossers living in the United States and 250,985 living in Mexico.

To those living in Mexico the question was asked: “In total, how much money (in dollars) do you expect to spend in the United States on this trip?” The responses varied but the median was $142.01. Considering that the 250,985 may be families of four, the median expenditure translates into better than $8.9 million a day ($3.25 billion a year), and possibly higher if the family-of-four figure is lower. For comparison, the San Diego Convention Center was worth $1.2 billion to the region’s economy last year.

United States residents returning from Baja were asked: “In total, how much money did you spend in Mexico on this trip?” The responses also varied but the median was $144.32. So the potential spent daily in Baja by the 104,915 visitors, depending on family size returning, can range from $5 million ($1.5 billion annually) to $7.5 million ($2.7 billion annually). Whatever the amount, it is a significant portion of Baja’s $15 billion annual gross regional product.

As Sandag’s studies continue, we will have a greater picture of the potential economic disruption the binational region may suffer with border delays. Now we need to add to that study the potentially serious economic disruption that a major decrease in Baja tourism may bring.

Patrick Osio Jr. can be reached at posiojr@sandiegometro.com. The veteran consultant also has issued The Mexican Perspective, an intensive primer on business culture and protocol. Copies are available at hispanicvista.com/sales/book_sale.htm.