The Avalon Theatre is the oldest surviving movie house in Washington, D.C., and I am very lucky to live within an easy one-mile walk of the Art Deco-era building. Unfortunately, the Avalon’s owners shut it down a few years ago because it competed with other theaters they owned in town. Our neighborhood rallied to save the building and the theater, this time as The Avalon Theatre Project–a non-profit community-based organization. The Avalon thrives today, beautifully restored and offering both mainstream and independent films.

My connection with the Avalon Theatre Project is only as a small donor to its early fundraising efforts and as a somewhat regular patron. Usually the Avalon has brought me only good things, but my most recent experience at the theater dragged me down into the devious mindset of many taxpayers. A few weeks ago I made the mistake of seeing a French film called “Kings and Queen” at the Avalon rather than taking in the summer blockbuster “Batman Begins” at the local multiplex. This Frankish fiasco was so execrable–not to mention mind-numbingly long–that I nearly walked over to the box office to demand my $9.50 back. I should have, because I received absolutely nothing of value in exchange for my payment to this non-profit.

At that moment I had a thought, “Didn’t I just make a tax-deductible contribution to The Avalon Theatre Project?” Surely, my purchase of a ticket to see “Kings and Queen” constituted a contribution–this massively muddled movie had no entertainment or educational value to me (or anyone else seated near me in the theater, as far as I could tell). In fact, so angered was I by the contrast between the nearly unanimous rave reviews for “Kings and Queen” and the reality of the awfulness of actually viewing the movie that I felt I had been tricked into donating not only my money, but also two hours of my time on an otherwise pleasant Friday evening.

Fortunately, my legal training overcame my pique. I knew the tax code wouldn’t let me deduct the value of my time as a charitable contribution. But as a lawyer I knew I could deduct the cost of my travel by car to and from the theater at the rate of about 42 cents per mile. (I wish I hadn’t walked.) Again, thank goodness for my legal training. I quickly concluded I couldn’t deduct my travel costs of about 84 cents (if I hadn’t walked) because I didn’t go there to do anything on behalf of The Avalon Theatre Project. All I did was waste a bit of my life groaning through the cinematic chaos of “Kings and Queen.” Still, I figured I had a deduction of $9.50 coming to me. Right?

Wrong. Mine is the kind of deviously shallow thinking by donors and some lawyers that has caused conniptions in Congress and the IRS. Last year Congress finally acted by clamping down on car-donation programs where many taxpayers took large deductions based on wildly inflated appraisals of the fair market value of their often junky cars, trucks and boats. The problem was that common sense was often in short supply when people interpreted the phrase “fair market value.” The solution was to require formal appraisals of the vehicles before the taxpayer could claim a deduction.

But the problem of coming up with reasonable valuations of noncash contributions to charities persists in other areas because too many people are willing to miss the point of charitable deductions.

Historic facade easements are a good example. Preservation charities ask the owners of historic buildings to hand over legal rights to facades of their buildings. Because the owners can no longer make changes to those facades, their property values often decline. If that occurs, owners can claim a deduction equal to the reduced value of their property.

But who decides how much? Your brother-in-law real-estate agent? What if local historic district zoning already prevented you from altering the front of your building? Did you really give anything to the charity at all? Many taxpayers answer “yes.”

Such willful missing of the point and otherwise sloppy thinking has gotten even the non-profit sector to lobby for tightening up the rules on noncash contributions. The integrity of a voluntary tax system and the credibility of the non-profits themselves demand that they do so. Lamenting the loopy logic of tax evaders is not enough. You gotta change the rules.