One of the most cherished assumptions of organized labor is that a hefty increase in union membership would be good for the nation.

This is simply untrue. Having a union may be good for some workers. And certainly, some companies have botched employee relations so badly they deserve to have their workers represented by a union.

But for the economy as a whole, a large increase in the number of unionized businesses would be a tremendous drag on growth, especially in dynamic sectors such as technology.

Yet that's exactly what union backers in Congress are pushing for with the misnamed Employee Free Choice Act. The measure was passed Thursday by the House. It's expected to receive a more skeptical reception in the Senate — where it deserves to die.

The bill would allow a union to be established when a majority of workers sign check cards giving their consent. Such a system would effectively supplant the current process of using supervised elections to decide on union representation.

The check-card system would deny workers the protection implicit in a secret ballot, leaving them exposed to intimidation from union organizers who collect the cards.

Unions are pressing for this change because they know it would mean many more bargaining units, many more members and a vast increase in the flow of mandatory dues revenue.

Yet a massive increase in unionization would lead to economic stagnation as the inflexible work rules of labor contracts percolate through more American businesses.

The economy grows by adding new work to existing work, a process that is spontaneous, unpredictable and often disruptive to the typical union contract, which divides work into strictly defined categories.

I've often quoted the late Jane Jacobs in this space. She was known mainly for writing about cities, but she also wrote about the nature of economic growth, which she argued took place mainly in broadly diversified urban environments.

Unions tend to retard growth because it is in their interests that industries remain the same, in terms of technology. Any change can put unions in conflict not only with management but with the new innovations that make familiar products obsolete.

"Only in stagnant economies does work stay docilely within given categories," she wrote. "And wherever it is forced to stay within prearranged categories — whether by zoning, by economic planning, or by guilds, associations or unions — the process of adding new work to old can occur little if at all."

It's no accident that the companies that produce the most amazing innovations of our day are largely non-union. The process of adding new work to existing work would be retarded if entrepreneurs must face down unions whenever someone comes up with a new idea that upsets existing arrangements.

Almost as bad as the check-card system is a provision in the bill that would impose binding arbitration when union and management cannot agree on an initial contract.

Normally, it takes several months to a year to achieve an initial contract. But the bill would give both sides only 90 days to reach agreement, after which federal mediators would be called in. If the two sides are still unable to settle, the dispute would go to arbitration.

This would dramatically tip the balance in favor of unions. If management takes a tough line, the union could simply run out the clock, knowing it will likely receive a better deal through the arbitration process — which would be controlled by individuals with no stake in the company's future.

The secret ballot protects workers from intimidation from both labor and management. It has worked well for decades, and it should be retained.