who had not applied for a patent. Scientistswho reported refusing to share data weremore than twice as likely to be the victims ofdata withholding as those who had not.

“Selectively withholding research resultsfrom the most productive and commerciallyactive researchers could slow the progresstowards understanding the causes and curesof human disease,” warns Campbell.

The National Institutes of Health issuedguidelines last year encouraging the sharingof materials and data, but some scientists saythese need tightening. Campbell and his col-leagues make several recommendations toinstitutions regarding data sharing. Forexample, they suggest that senior staffshould be encouraged to help junior scien-tists gain access to results and materials fromother researchers and that professional soci-eties and funding agencies should encouragedata sharing.

“We welcome the study,” said JonathanKnight, associate secretary of the AmericanAssociation of University Professors. “Thestudy shows some concrete dimensions tothe problem.” Rex Dalton

the south, with the northern populationremaining safe for at least another fiveyears.

Scientists are concerned that theplans could herald the end of aninternationally valuable long-termpopulation study, and hope that SNHwill consider leaving the northern-blockpopulation alone.

“The long-term red-deer study hasprofoundly influenced our under-standing of important conceptual issuesin evolutionary biology — for example,sexual selection and sex allocation —and population biology, includingfactors such as density dependence andthe maintenance of genetic variation,”says Andrew Cockburn, a behaviouralecologist at the Australian NationalUniversity in Canberra, who is familiarwith the studies.

“The research also has had greatconsequences for our understanding ofthe management of ungulatepopulations. Perhaps most important,the study has clearly not run its course,as fascinating recent results on sex ratiosattest. It would be very disappointing tosee the work come to an end.”

Josephine Pemberton, a populationbiologist at the University of Edinburghis one of the authors of a recent paper onsex ratios in Rum red deer (see Nature399, 459; 1999). She says the deer, whichare individually monitored, “should beseen as a national and internationalresource for research and educationwhich has its own intrinsic value”.

Usher acknowledges the researchers’concerns. But he argues that they shouldnow be addressing the substantialopportunities for researching how adeer population at normal densitywould change in a more diverselandscape.

Another scientist suggests that Rumcould be treated as a demonstration case for other areas of Scotland wheresimilar replanting is occurring next tohigh-density deer populations. “Youwould have to accept high-densitypopulations of deer in areas adjacent towhere conservationists want to plant,”says Steve Albon, from the Institute ofTerrestrial Ecology in Banchory,Scotland.

Although SNH says it is committed tothe concept of Rum as an outdoorlaboratory, it wants to limit futureresearch. A spokesperson said “we dohave a difficulty with current researchwork, which is conflicting with themanagement of the reserve”. SNH’svision includes increasing visitornumbers to the island and, in the long term, allowing more people to livethere. Natasha Loder

WashingtonResearchers who refuse to share data mayprovoke others to withhold results fromthem, according to a study by health-policyanalysts at Harvard Medical School.

The study found that young researchers,those who publish a lot, and investigatorsseeking patents are most likely to be deniedaccess to biomedical data and reagents. Italso found that researchers who withholddata gain a reputation for this and have moredifficulty in obtaining data from others.

The study, whose results are published inthe February issue of Research Policy, wasconducted by a research team led by sociolo-gist Eric Campbell at Harvard MedicalSchool’s Institute of Health Policy.

The team surveyed 2,366 randomlyselected scientists — both clinical and non-clinical — at 117 US medical schools. Over-all, 12.5 per cent said they had been deniedaccess to other academic investigators’ data,excluding article reprints, during the pastthree years. This corresponds with previousfindings by the team and other groups.

But, by examining the ‘victims’ of datawithholding, the team identified those expe-riencing the most difficulty. For junior staffmembers, the team found that 13.5 per centwere denied access, compared with 5.1 percent of senior researchers.

The relationship between data withhold-ing and researchers’ publishing records dur-ing the preceding three years was striking: 7.7per cent of those who had published 1–5 arti-cles had had data withheld from them, butthis rose to 28.9 per cent for researchers whohad published more than 20.

Among those who had applied for apatent, 30 per cent had been refused access todata, compared with 9.4 per cent of those

Jonathan Pollard, an American who spiedfor Israel, in 1986. They were tightened up in1998 following of the arrest of Wen Ho Lee, aLos Alamos scientist who is suspected of spy-ing for China.

At their meeting last week, Richardsonand Israeli officials also discussed coopera-tion on technical means of monitoring theNuclear Non-proliferation Treaty.

Israel has declined to sign the treaty andhas maintained a deliberate silence about itsnuclear weapons programme. However, thecountry is widely believed to have built up anuclear arsenal. Haim Watzman

news

6 NATURE | VOL 404 | 2 MARCH 2000 | www.nature.com

Young, worldly and unhelpfulall miss out on data sharing

JerusalemIsraeli scientists will have an easier time vis-iting and working with laboratories run bythe US Department of Energy under anagreement signed last week.

Under the terms of the agreement, signedby US Secretary of Energy Bill Richardsonand Israel’s Minister of National Infrastruc-ture, Eli Suissa, Israeli scientists will nolonger have to undergo thorough andlengthy security clearances before beingallowed to visit the laboratories.

These clearances were imposed on Israeliscientists in the wake of the conviction of

US eases Israelis’ lab access

▲

Researchers denied access to data over thepast three years

Researcher Percentage of requests denied

Has MD 9.2

No MD 17.7

Publishing record:

1–5 articles 7.7

>20 articles 28.9

Applied for patent?

Yes 30.0

No 9.4

Member of federal review board/study panel?

Yes 20.2

No 8.6

© 2000 Macmillan Magazines Ltd