As shown in the figure below, the average numbers of registered parishioners and Mass attenders reported by pastors vary by region. If you are in a typical parish in the West you have likely seen significant growth in the number of registered parishioners (+394) and Mass attenders (+93) since 2008. To a slightly lesser extent this is also occurring in the South (+147 registered and +25 attending). Thus, Catholics working in parishes in the South and West are more likely than those in other regions to "feel" the Church growing.
By contrast, those in the Northeast may find reports of growth in the Church unbelievable based on their own personal experience. In this region, a typical parish has lost 167 registered parishioners and 22 Mass attenders since 2008. Parishes in the Midwest are also likely seeing fewer in the pews on Sunday (14 fewer attenders) but are not experiencing the same losses in registered parishioners (+33) as Northeastern parishes, on average.
These changes are part of a long process of population realignment in the Catholic Church in the United States (problematically, parishes have not similarly realigned). In the last 65 years or so Catholics have left urban areas and parishes (i.e., historically Catholic immigrant communities) in the Northeast and Midwest for suburban homes and parishes or have moved even further into the "Sun Belt" in the South and West. Both migration and immigration have been important with new Catholic immigrants more often residing in the South and West as well. In 1950, 24% of Catholics in the United States lived in the South and West combined. Today, these two regions account for 49% of the Church's U.S. population (for more about these changes in a broader context see this recent post). It's as if two Churches are simultaneously emerging in United States. One is closing parishes and feeling decline while the other is bursting at the seams (...and the news media too often seem only interested in telling one of these tales).
About the National Survey of Catholic Parishes (NSCP)
The research was made possible through funding provided by SC Ministry Foundation and St. Matthew's Catholic Church in Charlotte, NC. In October 2013, CARA began sending invitations to 6,000 randomly selected parishes (5,000 by email and 1,000 mail) to take part in the National Survey of Catholic Parishes (NSCP). Stratification was used. The total number of parishes randomly selected in each diocese was determined by weighting the diocesan averages of the percentage of the Catholic population and the percentage of Catholic parishes in the United States in each diocese as reported in The Official Catholic Directory (OCD). This stratification ensures that parishes representing the full Catholic population were included rather than a sample more dominated by areas where there are many small parishes with comparatively small Catholic populations. A total of 486 email addresses were not valid and 68 of the mailed invitations were returned as bad addresses or as being closed parishes. Thus, the survey likely reached 5,446 parishes. The survey remained in the field as periodic reminders by email and mail were made until February 2014. Reminders were halted during Advent and the survey closed before Lent in 2014. A total of 539 responses to the survey were returned to CARA for a response rate of 10%. This number of responses results in a margin of sampling error of ±4.2 percentage points at the 95% confidence interval. Respondents include those returning a survey by mail or answering online. The survey consisted of 169 questions and spanned eight printed pages. A slightly smaller national CARA parish survey, including 141 questions from 2010, obtained a 15% response rate. Response rates for CARA parish surveys are correlated with the length of the questionnaire. Responding parishes match closely to the known distribution of parishes by region. Data for sacraments celebrated also match the OCD closely.