Friday, 17 May 2013

The Price of Wool and Economic Growth

You know how most comments sections are, well, terrible?* Not this one. Gerald Silverberg blogs on the New Zealand 1951 GDP data point and the Reinhart-Rogoff mess. I'm going to leave refereeing on Reinhart-Rogoff to Justin Wolfers. But just look at the depth of wonkery that goes into a single cell in an Excel spreadsheet. Careful data collection and distribution is ridiculously undervalued.

Gerald tries working out New Zealand growth rates for 1946-1952, contrasting Maddison's data with others. The Reinhart-Rogoff data doesn't look like Maddison's. Then commenters, likely including at least one data maven from the bowels of the NZ bureaus, start helping out.

Commenter Oscar first points to an FT piece showing that Maddison uses calendar years while the Stats NZ series uses March years. Then Silverberg starts wondering whether 1951 was due to the waterside lockout or to the wool price boom, quipping:
Who would have thought that you would have to become an expert on NZ wool exports and labor relations in 1951 to decide if public debt affects economic growth.
It gets much much wonkier from there. Mark Sadowski provides a short history of the waterfront dispute and the wool boom:
I was convinced from the start of the HAP/R&R controversy that the New Zealand part of this story was explained by the 1950-1951 New Zealand Wool Boom and not the 1951 New Zealand Waterfront Dispute.

The 1952-53 New Zealand Yearbook shows that wool sales were 47.1 million NZ pounds in 1949-50, 107.5 million NZ pounds in 1950-51 and 52.7 million NZ pounds in 1951-52.

Most of this was caused by a change in price, not a change in output. The average price of wool rose from about 38 NZ pennies a pound in 1949-50 to 88 NZ pennies a pound in 1950-51 and fell back to 40 NZ pennies a pound in 1951-52. (There were 240 pennies to a New Zealand pound.) Production was about 298 million pounds in 1949-50, 294 million pounds in 1950-51 and 315 million pounds in 1951-52.

According to the HAP/R&R dataset New Zealand's nominal GDP (NGDP) was 1.101 billion NZ pounds in 1949, 1.396 billion NZ pounds in 1950 and 1.446 billion NZ pounds in 1951, so that was a substantial proportion of New Zealand's economy.

A good paper about the New Zealand Wool Boom is here.

I can't locate a free copy, nor can I save a PDF file I can cut and paste but I would summarize the episode as follows.

Demand for wool had been strong since WW II ended but supply had been unresponsive to elevated prices. When the Korean War started in June 25, 1950 there was an immediate elevation in the price of wool. Between that date and March of 1951 the price of wool went up two to three fold depending on grade (lower grades went up more, mainly because that was the kind of wool the military was buying). Demand wasn't simply driven by US military stockpiling as retailers actually used rising prices to induce even higher sales.

In January 26, 1951 the United States Office of Price Stabilization (OPS) imposed a general price ceiling measure designed to freeze the pre-war price-wage structure. The price ceiling on wool brought trading in Boston (the central US wool market) to a standstill and caused US participation in New Zealand wool auctions to more or less cease. This led to falling New Zealand prices until February 7 when an emergency exemption was granted to the US military through April 1. This caused prices to recover but once the exemption expired prices fell sharply. By June 1951 they had fallen by 50% and by March 1952 they had fallen a total of 70%.

Now, my sense from reading the history of the Waterfront Dispute is that it was less a strike than a lockout. The government brought in 3000 troops an unknown number of scabs to keep the dockyards running, and thereby crush the union.

The 1954 New Zealand Official Yearbook shows the Cargo Manifest Tonnage "cleared" (exports) fell from 1,163,934 tons in 1950 to 1,129,629 tons in 1951. It rose up to 1,173,577 tons in 1952.

In other words the mass of cargo moved fell by only 2.9% and rose by 3.9% the following year.

What about the actual value of exports? Exports *rose* from 183,752,000 NZ pounds in 1950 to 248,127,000 NZ pounds in 1951, and fell back to 240,561,000 NZ pounds in 1952

Wool exports rose from 74,653,000 NZ pounds in 1950 to 128,176,000 NZ pounds in 1951 and fell to 81,998,000 NZ pounds in 1952. Note that wool exports increased by over 70% in 1951 and amounted to nearly 52% of all exports that year.

So it would appear that the 1951 Dockyard Dispute had little effect on actual exports. [note: links tidied from source]
And all of this over one cell in a rather large Excel table. Raise a toast tonight to the wonks whose work provides every cell of every spreadsheet on which we rely.

* Except at Worthwhile Canadian Initiative, somehow.

1 comment:

  1. Thanks for the link to the NZ wool/waterfront issues.

    It turns out both Maddison and StatsNZ are for fiscal years April 1 - March 31 in the relevant period, but Maddison dates from the starting day and StatsNZ from the end one, so the two series lag each other by one year. Also, the StatsNZ version of the Maddison index has a typo error for 1946 (they're planning to correct it soon)!.

    I'm just finishing up a "definitive" blog on NZ vs. Reinhart-Rogoff based on conversations with NZ statistical experts. It should be availabe in the next few days on my blog, so stay tuned!