Prominent Brexiter Andrew Lilico, I see, argues that we could avoid the uncertainty created by triggering the Article 50 process by not doing so:

The Treasury says an instant triggering of Article 50 post-referendum would be a driver of uncertainty. In which case, maybe don’t do that?

Indeed. Article 50 of the Lisbon Treaty lays down the process for voluntary withdrawal from the EU. You trigger it if you want to leave the EU. If you haven’t, you haven’t left the EU. Not triggering it – staying in the EU – would indeed avoid quite a lot of uncertainty.

But, Andrew, we could go one better. We could completely eliminate it. All we need do is vote to stay in.

A couple of thoughts on the economic consequences of #Brexit. HM Treasury, the Institute for Fiscal Studies, and others have published their efforts to forecast the short- to medium-term impacts of leaving the EU, and it’s fair to say none of them are good. The point I would like to highlight is that everyone seems to expect a big – 15% is a consensus number – devaluation in sterling post-Brexit.

I’m usually quite a “cheap pound” guy, so you might think I’d see this as an offset to the risks of Brexit. Actually I don’t, and here’s why. Just as a “strong” currency isn’t good in itself, but instead good for some groups in society and bad for others, a “weak” currency is good for some people – exporters, basically – and bad for others – importers, basically. A fall of 15% in the sterling trade-weighted index will help exporters in that it’s an immediate 15% price cut, and harm importers by the 15% increase in their prices. On balance, you’d expect it to reduce the current account deficit by 15% * some elasticity parameter.

It’s not that simple, though – there’s the famous J-curve effect. It might take time for exporters to increase their volumes, while import prices go up straight away. As a result, devaluations often have a contractionary effect immediately, and then a greater, expansionary one later. The problem, in the Brexit scenario, is that we propose to do something that will induce a substantial devaluation at the same moment that we commit ourselves to a whole lot of uncertainty regarding trade with Europe.

The case for it all turning out OK is basically a bet that the lower sterling trade-weighted index will lead to enough growth in export volumes to make it up. However, we’re meant to be taking this bet just at the time we do something that’s likely to constrain volumes on about 44% of our exports, even if only temporarily. Also, a lot of export-heavy companies are manufacturers integrated in international supply chains, who probably use quite a lot of intermediate products sourced from inside the EU. These companies will see their input prices rise sharply, while they may not be able to take advantage of the cheap pound on about half their market. As a result, they will experience quite a dramatic margin squeeze.

I can certainly see this leading to a beast of a J-curve recession, even if it doesn’t manage to push the housing market off the wall. One important trigger for a big drop in sterling, by the way, would be a drop in foreign portfolio investment in the UK. A hell of a lot of that is real estate, and there is already evidence of investors putting purchases on hold.

Before you all write at once, I stick with the 44% number. This has been criticised due to the so-called Rotterdam effect, where goods going to the wider world get trans-shipped through EU load centre ports like Rotterdam, Antwerp, or Hamburg, and therefore counted in the port statistics as exports to the Netherlands, Belgium, or Germany. There’s a good account of it here. I do not accept that this is a problem. Rather, I do not accept that it is a valid argument that European trade is less important than we think.

If shippers in the UK choose to ship to, say, China via Rotterdam rather than direct ex-Felixstowe or Southampton, they presumably do so for a reason, typically that bigger volumes and bigger ships mean lower freight rates and more choice of routes and sailings. There is no reason, I think, to expect Maersk or whoever to call at UK ports more often post-Brexit. Shipping via Rotterdam to somewhere extra-European represents trade with the EU in that the UK imports port services from the Netherlands, paid for out of the revenue from exporting. If we had a port the size of Rotterdam, we certainly wouldn’t discourage European shippers from using it! And of course, we do – just it’s an airport, and it’s called Heathrow, and just listen to the business lobby hollering for more capacity there.

In conclusion, one of the contradictions of Brexit that bothers me is that its strongest advocates seem to believe that relatively petty regulatory burdens are enormous restraints on the economy, whose removal would lead to a surge of growth, while they also seem to believe that incurring even relatively petty trade barriers would mean, well, nothing much. You can’t have it both ways. Either the economy is robust to petty interference, in which case we might as well stay in, or it’s not, in which case we surely have no business putting a new layer of it between us and Europe. After all, it’s unrealistic to imagine the electorate ever agreeing to some sort of Donner Party libertarian utopia – we wouldn’t be swapping open trade, with levels of regulation that don’t seem to do German exporters any harm, for a tariff, but zero regulation. Instead we’d likely get a worse relationship with Europe by quite a lot, offset by a few doubtfully useful regulatory changes at the margins.

I find this baffling. Perhaps, in the end, the belief is that even trivial regulatory changes would be transformative, and the relationship with the EU would, well, somehow turn out OK in an unspecified manner. That strikes me as too many leaps of faith for one lunchtime.

PS – don’t trust me, ask a Felixstowe docker!

It will make a difference. FXT will surely suffer as they will no longer be able to tranship to R’dam and elsewhere without documentation as they can now. Why would shippers go through two lots of clearance procedures when they can cut FXT out and ship straight to the continent?