Last month economists were announcing that the magic number had finally been arrived at. Meaning, the price of gasoline had finally risen to a price that changed the behavior of Americans. That number was $3.50.

That price doesn’t look so bad right now. Over the Fourth of July weekend, it had gained another 65 cents — over 18 percent in a month. For a little while, it had looked as if consumers just were not going let it surpass $3.99. The purely psychological barrier of the number four at the beginning of any price was changing minds very effectively and immediately changing bank balances.

But the number of consumers worldwide grows every day, while the number of crises (real or imagined) that threaten the tight supply of oil seems endless. So the price of oil has not been stopped by the reluctant American driver alone. Few believe the price will drop anytime soon, and we now must face reality of life over four dollars a gallon.

Over four, middle class families that might normally drive long distances to a vacation spot aren’t. They’re not flying either, because of rising airline ticket prices (and ever-more creative fees) and cutbacks on the number of flights. So the demographic of tourists coming here shifts to those who would otherwise go to Europe except for a terrible exchange rate, and those from Europe who see everything as a bargain at 40 percent off (even gas). Or the phenomenon I witnessed just a couple weeks ago in Provincetown — plenty of rentals booked, but no one is going out.

Over four, those who shopped at BJ’s in Hyannis or Wal-Mart in Wareham check the price of the roundtrip first. Costing ten dollars before you even walk in the store, is such a trip worth it? How many mega-packs of toilet paper can a person buy, week after week? Better to go to Job Lot for some items, CVS for others, and Stop & Shop for the real groceries.

Over four, the farthest movie theater or restaurant is Dennis and Wellfleet. The Cape Cod Mall’s stadium seating comes at a premium, as does the gas of the mid-Cape. And it won’t be dinner and a movie, but rather dinner or a movie.

Over four, there are no more spur-of-the-moment trips up to Boston. In fact, what excursions up there are combined with about six other justifications, and ideally shared with another person. If they can’t be found, then the trip is postponed. Even if it is doctor’s visit.

Over four, the locations one would be willing to work shrinks dramatically. I once worked in North Falmouth, and the worst part was the long tedious drive — up to the mid-Cape highway, down to Route 28, over Route 151 and over. Now that commute would cost over $90 each week. That’s a substantial deduction made to a paycheck, especially in a area with 40% lower pay scale than Boston but a similar cost of living. Employment options narrow as the zone one can afford to work within shrinks. Unemployment grows, especially in outlying areas.

Over four, exurbia is dying. The outer suburbs of many cities are being hastened to the grave variable-rate mortgages and highly inefficient SUVs. Any place on public transportation is doing well, especially area within walking distance of city centers and/or on bike trails. That’s one treatment for obesity.

Over four, parents are telling teenager that (gasp) they will have to pay for their own gas, driving them to (double gasp) take jobs. Reputedly, these were the jobs they were unwilling to take before. Not exactly a revelation: people who need money will work for it, all other options failing. Except they’re now in competition with other jobseekers who cannot afford to drive further for work.

Over four means there is less, if anything, in savings to get many through another winter on the Cape. In a seasonal economy, one must make hay while the sun shines. The doubling of gas prices in the past few years, while wages have either stagnated or fallen in the mean time, is a recipe for disaster.

Over four, the arrival of the home heating oil truck will be greeted with the same dread as a root canal. No, worse. A root canal need only be done once. Heating one’s home is inevitable and successive. All other supplementary heating sources have risen, too — propane, wood and wood pellets. Unless you’re ready to install a solar hot water system or photovoltaic (electricity-generating) panels on your roof, or your neighbors or town are cool with your plans for a wind turbine, this winter will be extremely harsh on lower and middle class families in New England. Some will end up moving in together, at least for the winter. Others will see this as the last straw and move away. Some will turn down the thermostat, put on a sweater and hope the tank will last until the next paycheck comes in.

Over four offers a mixed bag: more togetherness, more exercise, more ingenuity on the one hand, while on the other, less opportunity, less business for local restaurants, less savings, more out-migration of working families and lower temperatures in senior’s homes.

Over four exposes our isolation and the vulnerability, in stark terms, of our local economy. We’ve never really had a solid foundation — more of a tent on the beach with the various poles leaning against each other (fishing, tourism, retirees). Long commutes for better paying jobs is no longer an option. Counting on seasonal visitors to have loads of disposable income left over after paying the cost of travel of housing is now a gamble. We must solve our own problems as we see them coming, rather than trying to hold up the tents poles during this hurricane.