Because of the unique multi-country design of SHARE, SHARE uses a mixture of sampling designs based on what was available for each country. The original SHARE sample included persons from Austria, Belgium, Denmark, France, Germany, Greece, Israel, Italy, The Netherlands, Spain, Sweden, and Switzerland. Both Denmark and Sweden used a stratified simple random sampling from national population registers. Germany, Italy, Spain, and The Netherlands used multi-stage sampling using regional/local population registers. Austria, Greece, and Switzerland used single or multi-stage sampling using telephone directories followed by field screening.
Austria, specifically, used a three-stage sampling design. The first-stage selection used a list of municipalities and political districts in areas where interviewers were located stratified by the combination of nine regions and three population size groups. The second-stage selected telephone numbers located in the the selection locations using a CD-ROM containing all registered telephone numbers. If a business phone number was selected, the next private number on the list was selected. The third-stage screened for age-eligibility from each selected number. All age-eligible households were included in the sample.
Denmark, specifically, used a simple random sampling of households using a family (household) register created by Statistics Denmark from their Danish Civil Registration System.
France, specifically, used a master sample of dwellings which was a subsample of the 1999 census plus a list of new dwellings built since the 1990 census. The master sample was stratified by region and degree of urbanization (divided into four categories). In urban units with more than 20,000 inhabitants, SHARE used two-stage sampling where districts in the selected unit were selected. In all other units, all households in the unit were sampled from. The final stage of sampling used systematic sampling with equal probabilities except for rural strata where SHARE first selected a sample of counties from the primary unit before the final sampling.
Germany, specifically, used a two-stage sampling approach. In the first stage municipalities are classified by district and size using a list of all 13,416 German municipalities. From each combination one municipality was chosen with probabilities proportional the the population size. In the second stage 80 persons were chosen from each selected municipality using municipal population and address lists listing address of people born in 1953 or earlier. For the main study 27 of these persons were selected with simple random sampling without replacement.
Greece, specifically, used stratified two-stage sampling. Starting with a list all 54 Greek prefectures, the first stage selected phone numbers by simple random sampling without replacement for each prefecture using a computerized telephone directory. In the second stage, interviews called all selected phone numbers to identify age-eligible households. All age-eligible houses were interviewed.
Italy, specifically, used a three-stage stratified sampling design. In the first-stage, municipalities were stratified by population size 50+ as of 2001 and by geographical location. The 11 largest municipalities were selected and other municipalities were chosen from all strata by simple random sampling without replacement. In the second-stage electoral divisions were chosen inside the selected municipalities using simple random sampling without replacement based on a list of electoral divisions from the Italian Ministry of Interior. The final stage was conducted in two phases. In the first phase an equal number of males and females were selected using gender-specific municipal electoral registers within the selected electoral division by simple random sampling. Once non-age-eligible persons were deleted, the males and women were selected using a 3/4 ratio by simple random sampling.
The Netherlands, specifically, used a two-stage sampling. In the first stage, municipalities were selected from a list of all 489 Dutch municipalities probability proportional to population born in 1954 or earlier using 2003 population statistics. At the second stage, households were chosen by simple random sampling from the selected municipalities using local population registers prepared by the municipality to uniquely list persons born in 1954 or before.
Spain, specifically, using a two-stage sampling design. At the first stage, census districts were selected probability proportional to the total population using a list of all districts by municipality. In the second stage, persons were selected using systematic sampling with a random start of 11 persons from each selected census district using population registers of individuals born in 1954 or earlier based on census and municipal registers managed by the National Statistical Office.
Sweden, specifically, used a simple random sapling of persons using the population register NAVET of the Swedish tax authority which includes all registered residents as of 2004 born in 1954 or earlier.
Switzerland, specifically, used simple random sampling without replacement to select telephone numbers using the telephone directory of Switzerland stratified by the dominating language of the region so that there was a German language region, a French language region, and an Italian language region. Phone numbers were then screened for eligibility.
In 2006 SHARE added three additional countries to its sample: Czech Republic, Poland, and Ireland. SHARE also added a refreshment sample in Belgium, Denmark, France, Germany, Greece, Israel, Italy, The Netherlands, Spain, Sweden, and Switzerland.
In 2010 SHARE added four additional countries to its sample: Hungary, Portugal, Slovenia, and Estonia. SHARE also added a refreshment sample in Austria, Belgium, Czech Republic, Denmark, France, Italy, The Netherlands, Spain, and Switzerland.
KLoSA Sample Description
The original KLoSA sample was selected as part of a stratified, multi-sage area probability design. The first component of this sampling framework is the probability proportional to size (PPS) systematic sampling of the 2005 South Korean Census enumeration districts after stratifying by the location (15 major metropolitan cities and provinces) and characteristic of the district (urban or rural, and apartment building or non-apartment dwelling). Households were selected within PSUs from a listing of households in the Census identified as age-eligible; that is, inhabited by at least one person 45 years of age and older.
In KLoSA, once it was determined that there was an age-eligible member of the household, all age-eligible household members were interviewed. As a result, there are households in the data in which more than one couple is interviewed.
The initial sample included 10,254 respondents age 45 and over. The second wave was conducted in 2008 and 8,688 respondents. The third wave was conducted in 2010 and 7,920 respondents. The fourth wave was conducted in 2012 and 7,486 respondents. There was no refresher sample in wave two to four.
JSTAR Sample Description
The baseline JSTAR sample included persons who lived in five municipalities in the eastern area of Japan. The municipalities are Takikawa city in Hokkaido, Sendai city in Miyagi Prefecture, Adachi ward in Tokyo, Kanazawa city in Ishikawa Prefecture, and Shirakawa town in Gifu Prefecture. Unlike other studies, JSTAR did not use a national representative random sampling but chose to conduct stratified random sampling with each of the five chosen municipalities. JSTAR used a two-stage approach. After diving household registry data which are sorted by address into groups, first-stage locations were randomly selected for each municipality. The second stage involved randomly selected 20 individuals from each selected location.
The second wave of JSTAR was conducted in 2009 and included the five original municipalities and two additional municipalities: Tosu city in Saga Prefecture and Naha city in Okinawa Prefecture.
The third wave of JSTAR was conducted in 2011 and encompassed the five original municipalities, the two municipalities added in 2009, and three additional municipalities: Choufu city in Tokyo, Tondabayashi city in Osaka Prefecture, and Hiroshima city in Hiroshima Prefecture.
TILDA Sample Description