The millennium bub

Abstract

How much do nonmedical factors affect the timing of conceptions, births and deaths? To test this, we estimate the effect of the millennium on conceptions, births and deaths. With a highly flexible empirical specification, we find large and significant increases in conceptions and births, and suggestive evidence of an effect on deaths.

Notes

¹ Some have argued that the millennium technically began in the year 2001. However, given that global attention focused almost exclusively on the year 2000, we refer to this as the ‘millennium’. To the extent that, some of the effects we test for actually occurred in 2001, it will attenuate our estimates.

² Other studies have found that changes in taxes and benefits can affect the timing of births (Dickert-Conlin and Chandra, 1999; Gans and Leigh, 2006a), marriages (Alm and Whittington, 1995; Sjoquist and Walker, 1995) and deaths (Kopczuk and Slemrod, 2003; Gans and Leigh, 2006b).

³ We are not aware of any policy changes that might have created an incentive to shift the timing of births, deaths or conceptions during this period. Our analysis does not span multiple tax years, since the Australian tax year runs from July 1 to June 30.

⁴ Since our focus is on effects that might be specific to June 28, June 29 and so on, we define a day of the year variable that is unaffected by leap years. In leap years and nonleap years, the day of year variable is 59 for February 28 and 61 for March 1. In leap years, the day of year variable takes the value of 60 for February 29.

⁵ We use the term ‘annual fixed effects’ because the effect usually spans calendar years. When analysing conceptions, we focus on the window around September 23, so the annual effects are simply year fixed effects. However, when analysing births and deaths, we focus on the window around January 1, so our annual fixed effects are offset by six months (e.g. the window Dec 1998–Jan 1999 has one fixed effect, the window Dec 1999–Jan 2000 has another fixed effect).