[What determines the market shares of the health funds in Israeli localities?].

Four health funds operate nationally in Israel, but their local market shares vary dramatically across localities. To identify the main localities' characteristics which affect the size of the market shares of the various health funds. A total of 60 Localities with more than 20,000 inhabitants were chosen. The following Localities' characteristics were retrieved for the year 2004: the market shares of the four health funds, average income, standardized mortality ratio (SMR), periphery index, the age structure, the distance from the nearest general hospital, the share of Arab population, and size. Four market share equations were estimated using SURE (seemingly unrelated regressions estimation), allowing for inter-equation correlations. The results show that the market shares of the different health funds are affected by different factors. Clalit Health Services' (CHS) share increases with the distance from Tel Aviv and SMR, and decreases with the level of mean income and the distance from the nearest CHS hospital. Leumit's market share increases only with the distance from a CHS's hospital. The market share of Maccabi Healthcare Services is higher in central localities, Jewish localities, small cities and further away from a non-CHS hospital. Meuhedet's market share is higher in big cities, rich and healthy localities, and in Localities which are further away from CHS's hospitals. These findings indicate that the presence of the health funds in different Localities varies according to the Localities' characteristics. There appears to be a market segmentation and "specialization" of certain health funds in specific populations, and of the other health funds in the rest of the population.