fish

Description

Wooldridge Source: K Graddy (1995), “Testing for Imperfect Competition at the Fulton Fish Market,” RAND Journal of Economics 26, 75-92. Professor Graddy's collaborator on a later paper, Professor Joshua Angrist at MIT, kindly provided me with these data. Data loads lazily.

Usage

data('fish')

Format

A data.frame with 97 observations on 20 variables:

• prca: price for Asian buyers

• prcw: price for white buyers

• qtya: quantity sold to Asians

• qtyw: quantity sold to whites

• mon: =1 if Monday

• tues: =1 if Tuesday

• wed: =1 if Wednesday

• thurs: =1 if Thursday

• speed2: min past 2 days wind speeds

• wave2: avg max last 2 days wave height

• speed3: 3 day lagged max windspeed

• wave3: avg max wave hghts of 3 & 4 day lagged hghts

• avgprc: ((prca*qtya) + (prcw*qtyw))/(qtya + qtyw)

• totqty: qtya + qtyw

• lavgprc: log(avgprc)

• ltotqty: log(totqty)

• t: time trend

• lavgp_1: lavgprc[_n-1]

• gavgprc: lavgprc - lavgp_1

• gavgp_1: gavgprc[_n-1]

Notes

This is a nice example of how to go about finding exogenous variables to use as instrumental variables. Often, weather conditions can be assumed to affect supply while having a negligible effect on demand. If so, the weather variables are valid instrumental variables for price in the demand equation. It is a simple matter to test whether prices vary with weather conditions by estimating the reduced form for price.

Used in Text: pages 443, 580

Source

https://www.cengage.com/cgi-wadsworth/course_products_wp.pl?fid=M20b&product_isbn_issn=9781111531041

Examples

 str(fish)