IF REPUBLICANS in Congress unite behind Donald Trump’s agenda, it will not be because they have changed their views on economics. Whatever Mr Trump’s plans for border taxes and fiscal stimulus, most Republicans still profess to support free trade and loathe government borrowing. Instead, unity is possible because two other goals bind the president and his party together. The first, tax cuts, is a usual priority for the party. But the second, deregulation, only recently rose to the same status. The call to cut red tape is now an emotive rallying cry for Republicans—more so, in the hearts of many congressmen, than slashing deficits. Deregulation will, they argue, unleash a “confident America” in which businesses thrive and wages soar, leaving economists, with their excuses for the “new normal” of low growth, red-faced. Are they right?

The straightforward motivation for Republicans’ deregulatory agenda is their disdain for President Barack Obama’s legacy, much of which was installed through regulatory fiat. The Affordable Care Act, better known as Obamacare, required bureaucrats to write thousands of pages of new rules; the Dodd-Frank financial-reform bill did the same. When legislation was not forthcoming, the executive branch threw its weight around instead. It asserted that the Clean Air Act gave it wide-ranging powers to fight climate change, and that the Clean Water Act let it clean up many more ponds and rivers than ever before. It expanded mandatory overtime pay for workers on low salaries. It banned telecom firms from favouring any one type of internet traffic. And its “fiduciary rule”, set to come into force in April, will force investment advisers to act in the best interests of their clients.

Republicans hate all this, saying Mr Obama’s fondness for red tape has crushed the economy. His regulations were, on the whole, bigger and bolder than what had come before. They caused ire on the right—and among bankers and polluters. Sometimes they rested on uncertain legal ground. The Clean Power Plan has been delayed by the courts and may yet be struck down (Mr Obama’s old constitutional law professor, Laurence Tribe, is among its critics). The structure of the Consumer Financial Protection Bureau, a new agency set up by Mr Obama, may yet be found unconstitutional. The so-called “administrative state” has plenty of critics who worry more about the growing power of the executive than about the particular ends Mr Obama pursued.

America’s underlying regulatory problem long predates the 44th president. Between 1970 and 2008 the number of prescriptive words like “shall” or “must” in the code of federal regulations grew from 403,000 to nearly 963,000, or about 15,000 edicts a year, according to data compiled by the Mercatus Centre, a libertarian-leaning think-tank. Between 2008 and 2016, under Mr Obama, about the same number of new rules emerged annually.

The unyielding growth of rules, then, has persisted through Republican and Democratic administrations (see chart). Several factors explain it. First, Congress has neither the staff nor the expertise to write complex, technical laws. So lawmakers happily let experts in government agencies fill in the blanks. What Congress does write itself, it writes sloppily. In 2015 the Supreme Court found “more than a few examples of inartful drafting” in the Affordable Care Act. One such error nearly saw the court strike down crucial parts of law; only semantic gymnastics saved it. The “Chevron deference”, a doctrine from a 1984 court ruling, gives agencies wide latitude to interpret laws when they are vaguely written. (Neil Gorsuch, Mr Trump’s nominee to the court, is not a fan.)

Second, America’s division of powers makes it easy for interest groups to defend any one regulation, tax break or policy. That forces administrations to solve problems by taping yet more rules onto whatever exists already, rather than writing something simple from scratch. Over time, this gums up the system, resulting in what Steve Teles of Johns Hopkins University has dubbed a “kludgeocracy”. This explains, for instance, why over half of Americans have to pay a professional to fill out their tax return for them (in Britain, for comparison, most people need not even complete one). Mr Obama’s regulations were kludgey. The Clean Power Plan, which forces specific emissions reductions on power plants, emerged after Congress failed to pass a cap-and-trade scheme. Unable to raise the federal minimum wage, the administration did what it could to boost wages with a reboot of an old overtime rule. (This clumsily mandates that workers on low salaries must get a 50% wage bump for work in excess of 40 hours a week, creating strange incentives for firms to add staff rather than breach the threshold.) Unified government does not stop kludges. Dodd-Frank, passed in 2010 when Democrats controlled Congress, micromanages banks’ balance-sheets rather than imposing exacting but simple capital standards.

Bureaucrats, busted

Yet the most important explanation for the proliferation of rules concerns the habits of Washington’s bureaucracy. It has for decades been bad at rubbing out old ones.

When a government agency writes a significant regulation—mostly defined as one costing more than $100m—it must usually prove that the rule’s benefits justify its costs. Its analysis goes through the Office of Information and Regulatory Affairs (OIRA), a nerdy outpost of the White House. The process is meticulous. The OECD, a club of mostly rich countries, finds that America’s analysis of regulations is among the most rigorous anywhere.

But once a rule has cleared the hurdle, there is little incentive for agencies ever to take a second look at it. So it is scrutinised only in advance, when regulators know the least about its effects, complains Michael Greenstone, of the University of Chicago. The OECD ranks America only 16th for “systematic” review of old red tape. (The leading country, Australia, has an independent body tasked with dredging up old rules for review.)

Politicians of all stripes realise that America has fallen behind. Mr Obama ordered agencies to trawl for anachronistic regulations and report on their progress twice a year. This produced some results. For example, in 2014 the Department of Transportation scrapped a rule requiring truck drivers to file a report on condition of their vehicle before and after every trip, even when they found no faults. The change supposedly saved the industry $1.7bn. But the deregulatory charge lost some momentum in Mr Obama’s second term, after Cass Sunstein, its champion, left his post as head of OIRA. Critics contend that agencies ended up using the clear-out as another excuse to write new rules.

The endless pile-up of regulation enrages businessmen. One in five small firms say it is their biggest problem, according to the National Federation of Independent Business, a lobby group. (Many businessmen grumble in private about the Obama administration’s zealous regulatory enforcement). Based on its own survey of businessmen, the World Economic Forum ranks America 29th for the ease of complying with its regulations, sandwiched between Saudi Arabia and Taiwan.

Regulators retort that firms’ complaints reflect only one side of the ledger—costs—and ignore the benefits that flow from, say, greater protection for consumers. For example, Mr Sunstein has argued that the Obama administration was an unusually good regulator, because the estimated net benefits of new regulations in his first term were more than twice what either George W. Bush or Bill Clinton achieved in theirs.

But totting up costs and benefits is hardly straightforward. An agency which supports a regulation can obviously nudge the numbers in a favourable direction. Bureaucrats must sometimes make value judgments. For instance, the Obama administration counted benefits to foreign countries when weighing up rules to reduce carbon emissions.

In any case, cost-benefit analysis ages badly. Without updating it, it is difficult to know how much old regulations weigh on the economy. One Mercatus working paper plugs the number of rules in each industry into a complex model of the economy. It finds that rules written since 1980 have dampened growth by about 0.8 percentage points a year.

Republicans like to put about that sort of figure, but it strikes many economists as implausibly large. Even those sympathetic to deregulation, like Glenn Hubbard, who worked in Mr Bush’s White House, are hesitant to forecast the growth effects of a regulatory bonfire, preferring to stress the benefits of tax cuts. Democrats, meanwhile, are scathing about the idea that rolling back regulations would pep up the economy much. Jason Furman, who advised Mr Obama, adds up the costs of Obama-era rules and says it is “impossible” to see how you would add even a tenth of a percentage point to growth by undoing them. (The Trump administration promises growth of 3.5-4%, up from 1.6% in 2016, partly on the back of deregulation.)

Yet regulation does cause some visible problems. Infrastructure projects are frequently bogged down in endless environmental reviews and consultations. An example is a project to upgrade the Bayonne Bridge, which spectacularly arches between Staten Island and New Jersey. Elevating the road so that bigger cargo ships could pass underneath required 47 permits from 19 different government entities, according to Philip Howard, a legal writer. Regulators demanded a historical survey of every building within two miles of the bridge, even though the project affected none of them. It took from 2009 to mid-2013, when building at last began, to satisfy all the regulatory requirements.

And that is unusually quick. Big highway projects approved in 2015 took an average of a decade to clear every bureaucratic hurdle, according to one study. It is little wonder that Mr Obama struggled to find “shovel ready” projects to kick-start with stimulus funds after the financial crisis. (Any infrastructure push by Mr Trump will probably run into the same problem.)

Regulation can also impede innovation in ways that are hard to foresee. In 1973 the Federal Aviation Administration (FAA), worried about loud sonic booms, banned civil aircraft from flying at supersonic speeds above America. But planes are now lighter, more aerodynamic, and contain more efficient engines, explains Eli Dourado of Mercatus. That makes them quieter. With start-ups trying to build commercially viable supersonic jets, Mr Dourado thinks the FAA should replace the ban with a maximum permissible noise level. The FAA has acknowledged the case for change, but it moves slowly.

Playing the long game

Detangling America’s regulatory mess requires institutional change. It does not require tearing up Mr Obama’s legacy. That, however, is what Republicans are focused on. By law, Congress, with Mr Trump’s consent, can overturn any rules that were written late in Mr Obama’s time in office—in this case, after June 2016. It has already scrapped a requirement that energy and mining companies disclose any payments they make to foreign governments. It has also blocked a ban on people deemed mentally unfit to manage their own finances from buying guns. The president has ordered a review of the Dodd-Frank law, which regulates the financial industry, and has advised public schools that they need not adhere to an Obama missive advising them to allow transgender pupils into the lavatory of their choice, or face losing their federal funding.

Yet there is some impetus towards long-term regulatory reform. Mr Trump has also signed an executive order requiring that for every new rule regulators write in 2017, they must scrub out at least two old ones, and eliminate as many regulatory costs as they have imposed. Critics say this will arbitrarily halt good regulation that passes a cost-benefit test. But it does at least provide some incentive for agencies to revisit their past decisions. Britain has had a similar system since 2011. Its “one-in, one-out” requirement, which has since grown to “one-in, three-out”, has unearthed some barmy rules, such as a requirement that people working for themselves at home should follow workplace health-and-safety laws. (Mr Trump’s policy lacks some of the finesse of Britain’s, which lets regulatory costs in one department be offset by regulatory savings in another.)

When they get around to institutional reform, Republicans in Congress will seek more power over regulators. One proposal would ensure a congressional vote on every significant new rule. Another would make it easier to challenge cost-benefit analyses in court. This worries wonks. Congressmen have neither the time nor the expertise to evaluate most regulations properly, argues Philip Wallach of the Brookings Institution, a think-tank. Enabling politicians or interested parties to block rules they dislike risks making policy more kludgey. In America’s lawmaking, Mr Teles argues, veto-points function as toll booths, at which proponents of a law must write in yet another complicated carve-out or handout.

Instead, Congress could beef up the institutions which scrutinise cost-benefit analysis away from the heat of politics. The obvious place to start would be OIRA, which has seen its budget fall by a quarter and its staff halved over the past three decades, even as the regulation it must scrutinise has proliferated.

Yet OIRA will always be under the command of the White House. So others argue that Congress should create an independent agency to scrutinise regulations on its behalf. It could be modelled on the Congressional Budget Office (CBO). Widely respected for its independent analysis, the CBO increases the ability of Congress to scrutinise the budget. A congressional regulatory agency could do the same for regulation, and could also continually recommend old regulations for the chop.

Better institutions would not solve all America’s regulatory problems. And some over-regulation, like zoning requirements that stop successful cities from expanding, is the fault of state governments. About a quarter of American workers require an occupational licence to do their jobs, in part because states have a foolish habit of outsourcing regulation to those who have an incentive to make it harder to enter their profession. States must fix such problems themselves.

It is clear, however, that the federal government should keep asking itself whether each of its vast number of rules is really necessary. If Republicans can see past their dislike of Obama-era policies and focus on a bigger prize—root-and-branch reform of the regulatory system—the economy will surely benefit. Whether the gains will be large enough to justify tolerating the more damaging parts of Mr Trump’s economic agenda is another matter.